TOPIC: Sea Cast - foam between hull and composite?

I am going to replace the transom and likely the stringers on a lake n sea caribbean with sea cast. Thought is to cut 6 slots in the transom skin that will allow the sea cast to start flowing into the old stringer cavities once the wood is removed. Sea cast adheres to itself so this would create a great bond between the stringers and transom.

Question; what is your opinion on either pouring the sea cast directly into the stringer cavity vs. laying some type of closed cell foam maybe 1/8" to 1/4" thick in the cavity first and then the sea cast on top of the foam? I have read about the need to avoid creating "hard spots" between the inner hull skin and stringers. Is there any truth to this? The lake n sea has 6 stringers.

Do I also need to put the same type of foam or rubber or other on the top of the stringer between it and the new floor?

Sea cast says pour it right in both for the transom and the stringers as it will bond with the existing fiberglass.

At this point I have removed the rotten wood transom and sliced open the top of one stringer to examine the condition and see how easily it would remove. I popped right out leaving a nice cavity. I will not open any more to maintain the integrity of the hull. I'll start a full project thread once I get further into the project.

Thoughts, opinions, examples from experience?

Thanks,
Eric