By way of example, we have 6 Trojan T125s and use an 80 amp charger which takes 3-4 hours to bring them up from 50 - 85% charge. Doubling my charger size would yield a 2-3 hour 85% charge. In both cases, the remaining charge to get to 100% takes a few more hours. In both cases, the total elapsed time to go from 50% to 100% charge is 4 to 5+ hours.
The morale of the story is batteries can only take so much charge and speeding up the process by playing with your controller serves only to shorten battery
AGMs have a capacity to recharge faster, as you know, but the total time difference to get a full charge of wet cells vs. AGMs isn't significant in most cases.
Therefore, as I implied, you may want to re-consider given the decrease you might attain in re-charge time vs. 1. whether you really need that increment of time, and 2. whether that time saving is worth the cost.