We've seen lots of similar platform projects - even on a C&C 35 MkIII !!
No reason it can't work. You'll still need a good, deep ladder
for ease of boarding from a swim.. the ladder
could be make to match the angles from the platform, up the transom, and even up against the stern railing if that works.. And it all needs to be well reinforced, as you say.
Do a good looking job and I don't think there'll be too many naysayers..the practicality outweighs any negatives and it's easier than taking a chainsaw to the transom to create a "modern" walkthrough .... In many marinas it may cost you a few bucks a month in moorage if they catch on.