Having more people does make moving things along a little easier and a cap is good compromise to make sure numbers stays at the sweet spot of being not too crazy to manage while also allowing things to be easier.

Though one thing I do like about the invite only aspect is that reserves/applications doesn't require me to sit there waiting for the exact moment things open to throw in my stuff like I did at my last capped game that also had public apps. And that was nice.

You can also have certain periods of open apps. Like when the TDM is up apps are open to the public but other times it's invite only? I do like the idea suggested to use TDMs in place of invites, as well.