Chaparral 162 XL Under Splashwell Modification

I asked this else where without any guidance. I hope at the very least someone can help me understand what this part of the boat is called so I can do more research on my own.

Per the image attached things are a bit cramped up in the back of my chaparral 162 xl. What I am looking for advice on is if there is a potential issue cutting the fiberglass to the left and right of the current bilge/stow away area (Red boxed in second image.. It sounds hollow, putting an endoscope in there resulted in not much info other than looking like bare fiberglass in there. I really want to separate the gas tank to the Starboard and the electrical to the port while leaving the splashwell/scupper open to drain to the bilge.

I am totally fine with bare transom in the rear with a hanging splashwell. I don't put anything of weight on there except tools when working. Is there a potential to lose stability on the water from such a modificataion? Has anyone tried something like this before because I was unable to find what I was even asking after a search. Ultimately I am worried about affecting the strength of the transom by moving these hollow fiberglass walls.
​​​​​​​
​​​​​​​https://i.imgur.com/AfG9fo6.jpg
https://i.imgur.com/PsUNSM5.jpg

Ayuh,..... Those areas are Usually filled with flotation foam,.....

Ayuh is the name of the part of the boat? Also sticking the endo scope in there I didn't find any at all. I'm tempted to just break out the reciprocating saw and cut a bigger square to find out. Thank you for replying!