haven't read through the crap poetry lol nobody got time for thatt but have experienced the same "i cant do that" - no agent yet, llms very eager to apply a bodge fix or something rather than going "this design is shit consider changing it pal lol", which is the "fix" i did myself.
multiplayer netcode isnt overly difficult to write unless you're at the highest lvl of complexity lol. it's not a black box, it's just transferring bytes around efficiently and keeping track of state, your "netcode" can literally just be bare tcp (+ssl), validation, and state, it's not that deep.