I think this may be a false choice because of the work pattern you might be used to. Assuming here, If you work in interactive sessions where it's open ended there is a boundary where you have done enough research/prototyping and you need to move to implementation and the permission scope has to change now. I think the realization that you might have is that if you're doing this then it's probably best to separate the automated AFK part from your initial research part.
Even for pure research/prototyping, you quickly run into the problem that your sandbox is either prohibitively minimal or overly permissive. Depending on the exact task, you may need GPU access, Docker/Nix socket access, ability to ptrace processes (gdb), run webfetches, etc. If I define a "research" sandbox profile to allow all of these, I might as well not have any sandbox at all.