I've already seen that there might be an interest in adding spawn waves to CTE, so I'll just get that one out of the way first.
So... Team lives. I've thought about them for a while, and yeah, they are an alternate win condition, but it feels like they dilute the main objective of the mode when you can alternatively "Pseudo-TDM" the enemy team and take all their respawns before the timer runs out.
Not that the team lives system should be taken out entirely, maybe at some point it could be improved upon, but a toggle for it in general would be nice.