I think dev needs to rethink about having an ntr path. TBH, TT without Red is not TT at all imo.
Storywise, the duality of MC and Red keeps things interesting, even with sandbox given that it made some sense as Red "forces" MC to do things outside of his comfort zone and /or think outside the box aka run errands that are boring but with hopes of achieving something.
In the NTR version, the sandbox becomes a chore, as MC is simply going around acting as a beta BUT still goes through a whole bunch of hoops in order to be cucked. The entire darnell becca chain, leading up to the shower and later classroom scene is just boring as well... Its a whole lot of mc internal monologue plus cliche ntr trope...sigh...
Simply put, without Red, the story becomes lackluster.