Help me understand my (Cristec) battery isolator?

[KeepInTune]

I'm working to increase my understanding of my systems in anticipation of an eventual house AGM to LFP upgrade. I would very much appreciate any help and insight...and thanks for your patience!

My boat (2021 Beneteau Oceania 40.1) has a Cristec RCE/150-1E-3IG isolator. (150amp -3 inputs). It connects an input from the alternator to distribute charging to my 3 battery banks (engine, house, bow-thruster). The dc layout shows the shore power charger is also connected into the isolator (it shows this in design and think it shares one of the positive lugs shown in pic).
In short -my understanding is that this isolator automatically diverts the alternator charge (and also ac-dc charger?) to the lowest charged bank.

My questions:
1: If I switch my 4x100ah AGMs to new 4x100ah LFPs (with starter and bow thruster remaining as AGM banks) -how will the isolator accommodate for this and manage the change? Is it an effective component for this design?

1b: My beneteau manual states that if the LFP upgrade option (replacing house AGMs with LFPs) is chosen, "the lithium batteries are systematically charged before the engine battery. They take all the charge.". Reading the manual and system layout, I'm assuming the same isolator is used even when the upgrade LFP batteries are chosen. Does this charging priority ("lithium first..") occur due to the inherent charge profile of LFP's over AGM's which will "force" the isolator to divert the charge to the LFP's; as in the LFPs will appears to be the lowest of the 3 banks until the LFP's are fully charged (then will charge the starter and bow-thruster banks as needed)?? (It's concerning to me that engine and BT would not be charged until house bank is full! What if house is at 1/2 charge and I'm needing reoccurring use of bow thruster which draws charge down? It's seems BT could quickly be inoperable! Not sure I like that design in priority.)

2: If there is a sudden shutoff from the (soon to be installed) BMS' of the LFP house bank -will this isolator simply drive the alternator charge into the starter and bow-thruster banks and therefore eliminate the potential alt damage? (I can't seem to get clarity on this from Cristec)

3: If I were to add an external alternator regulator (Wakespeed WS500 or Balmar 618) for added protection and alternator efficiency, how would this existing Isolator be utilized and wired up?

4: I have more questions..but let's start with these...

Any other thoughts or input on this system?

(note: I will be using a certified marine electrician to install or make changes. I simply want to be very well educated on my systems prior to upgrade)
Cristec layout and definition of the isolator use:

[svtickles]

1: If I switch my 4x100ah AGMs to new 4x100ah LFPs (with starter and bow thruster remaining as AGM banks) -how will the isolator accommodate for this and manage the change? Is it an effective component for this design?

I made the same change on my boat. The Cristec 60A isolator briefly sends power to the start battery since it's partially depleted after motor start, then sends power to the LFPs (regardless of charge under 100%).

When the LFP is full, the BMS stops charging and the start battery starts receiving additional charge.

There are two issues here:
1. It can take up to 12 hrs to fill the LFPs (with my poor Hitachi alternator) so the motor start battery is rarely fully charged. This is bad for the AGM battery.
2. When operating the windlass from the start battery, the start battery has insufficient charge and all the power is going to to the LFPs. So our boat will quickly run out of juice to operate the windlass. The motor is on, but the Hitachi is so weak at 30A supply it might as well be off.

1b: My beneteau manual states that if the LFP upgrade option (replacing house AGMs with LFPs) is chosen, "the lithium batteries are systematically charged before the engine battery. They take all the charge.". Reading the manual and system layout, I'm assuming the same isolator is used even when the upgrade LFP batteries are chosen. Does this charging priority ("lithium first..") occur due to the inherent charge profile of LFP's over AGM's which will "force" the isolator to divert the charge to the LFP's; as in the LFPs will appears to be the lowest of the 3 banks until the LFP's are fully charged (then will charge the starter and bow-thruster banks as needed)??

It's down to chemistry. LFP = zero resistance so isolator sends power there first.

What if house is at 1/2 charge and I'm needing reoccurring use of bow thruster which draws charge down?

Yes! That is problem 3. The BT won't have enough juice if it's relying on the motor start battery or alternator supplied power. Since the latter is all going to the LFP until that bank fills up.

2: If there is a sudden shutoff from the (soon to be installed) BMS' of the LFP house bank -will this isolator simply drive the alternator charge into the starter and bow-thruster banks and therefore eliminate the potential alt damage? (I can't seem to get clarity on this from Cristec)

Yes, after the LFP fills up and the BMS shuts down incoming power supply, the isolator will simply send power to the next customer. No risk of damage in this scenario since you have two AGMs in effect in parallel to the LFP.

3: If I were to add an external alternator regulator (Wakespeed WS500 or Balmar 618) for added protection and alternator efficiency, how would this existing Isolator be utilized and wired up?

The regulator needs to have a temperature sensor. My boat has a Sterling AtoB 80A device which is designed to reduce charging and prevent the alternator burning up due to long operation at full capacity. Since the LFP = zero resistance, the alternator feels compelled to provide full charge at all times. So yes, you need to have a similar device with temperature sensor to prevent the alternator overheating.

Solutions:

I'm solving the BT and windlass supply issue by having a dedicated battery on the bow to operate them. A DC-DC charger will take power from the service bank and keep the bow battery full. The Victron DC DC will stop charging if the service bank hits below a set voltage. The issue with this approach is that the 12v charger is slow (30A max) so the battery needs to be at least 100Ah otherwise I run the risk of running out of power when I need it most. An alternative to the DC DC is to simply use a 120A relay from the service bank.

Another possible (very cheap) solution is to have a switch between the Cristec isolator and LFP. Turn it off and the isolator will send all the juice to the other customers. Just a pain to remember to do this every time whilst lifting anchor or going into marina; and put it back on afterwards.

A further option is to insert a relay between the motor start battery and service bank to ensure the motor start is always full.

[KeepInTune]

Oh wow --thanks so much! Your insight really helps.
Quick clarification:
-The windlass draws power from the house bank (not starter bank), so that should alleviate the concern about going low on that potential issue (engine is required to be on to use windlass)
-The bow thruster has a dedicated 2xAGM bank connected through the Isolator. So if depleted this bow thruster bank won't get charged back upuntil the (new LFP) house bank is full. Then same with engine bank I assume. I would think the preference would be to ensure the starter and BT banks re-charge would have priority over house.