Project M: Red Version is designed to be a project that adds Pokémon Trainer (or as I'll refer to him here, Red), back to Project M. Obviously, there's a stigma of regarding Red due to his gimmicks and relation to Brawl. I can say with certainty that this project aims to bring Red back with no change to Project M's core gameplay. Things like Stamina and Switching are to be removed entirely. Switching may return as an easter egg, like a taunt or such but that's a long term plan.
Of course, PMDT didn't plan for Red to be present in 3.6, leaving behind many issues. These include issues with coding, switching, the game not being ready for PT to be there, and a general lack of consistency. These are all things I aim to adress. Many stages added in Project M don't support Red and his background shenanigans. As such, that's 69 stages that need looked at and evaluated. So while the main project won't be out for a while (due to lack of team members, though I'm hoping to get people interested, so if you want to help, check out #project-m-red-version in the Brawl Modding Workshop Discord), I'll be releasing the stages to be compatible with Brawl and Project M, with UI included for both. Once the core project is done, I'll be looking into doing other stages for other projects.