Lots have, i did it on 20SF restore and am using it on my current 23 restore as well. Plenty of examples if you use the search feature!
If you have any specific questions feel free to ask and I'd be glad to share my experience.
General suggestions:
- Use the 26lb Bluewater density, not the 15lb. 28lb density Carbon Core (same type of material, different company) is a good alternative
- Use either (1) 1.5" sheet or (2) 3/4" sheets epoxied together to get 1.5" core thickness.
- Use luan or cardboard to make a template of the transom to use to cut the Coosa
- It cuts and shapes easily, so any tool you use on wood will work for Coosa
- Take pictures and document it here!