Well, someone filled the transoms with foam via this hole, and seems unlikely anyone else would have done this. And it was covered with the non-skid just like the other steps and matched 100% so unlikely it was done after the fact or I think it would be noticeable as matching the non-skid 100% would have been a challenge, but I am open to thoughts.
Keep in mind that it was totally unnoticeable until the "plug" started to sink a bit and then it started to show as an indent under the non-skid. For the first 4.5 years we owned the boat, never saw it at all. So, if the plug
were to hold long enough, you may not ever know unless you have changed out the non-skid.
The foam comes all the way up and fills the hole, it provides no access to anything. 2" is certainly not big enough to get a hand into. I am pretty sure it was not done to gain access to anything. And no one would have drilled the same hole 2x once they realized it was full of foam and didn't get them anywhere the first time.
I have added an access port (4") on the side of the port transom to gain access to things, and has worked very well and no issues with it, just FYI. Getting to the boarding ladder would still be tough though. On ours however, the ladder used tapped screws into the bottom step. So if it were to leak (or not hold well anymore), and the screws didn't hold, would just re-fill the holes with epoxy and tap new holes for the screws. Not ideal as it does not have nuts/backing on it, but has been ok for 15 years.
I sent a note to FP about this as well, as I had asked them, before I removed the non-skid, what the indents were from. The guy that answered said it was for the emergency
tiller, however, there is no such accommodation for an emergency
tiller on our boats. If I ever get a reply back from him I will post it here as well.