I feel like this would have a number of benefits:

• It makes the timing more consistent across categories

• It allows runners to check their lap times without losing time

• It removes menuing from the run, which isn't something you need to consider in the rest of the game

If you're worried about people stalling between rounds, Celeste has a similar thing with its IGT timer, and they basically just say "don't take too long between levels" and it's all fine there.

That would enable players to take as much time between levels as possible, which I don’t think fits the category.

Again, other games with IGT (or even RTA with custom scripts to remove time in menus) have things like this with no problems. I mean, if you're running a game and take 3 minutes between every character, attempt sessions take way too long to get in enough practice.

Also, having timing like this opens up situations where you press the flag like, a frame too early causing your run to be null and void. Also it means that the mods have to check every run to make sure they reach the finish line.