I don’t think there is a way to actually inspect an IP’s chainplates, not really as they are almost inaccessible, and they under a layer of glass.
No sure I would go external, but if you do try to get someone who is knowledgeable to advise you, or at least go big to spread out the load.
The
hull up that high isn’t really all that thick.
The
layup on an IP is not excessive, maybe .25” on average?
Original design it’s my opinion relies a lot on the hull to deck joint for its strength