When I launched my Insurgency server Red Death Squad on Jan/01/2024, I modded 6 vanilla maps to have playable Checkpoint gamemodes:
Kandagal
Peak
Panj
Station
Uprising
Ministry Night
At some point, I discovered issues with Uprising which caused me to disable that map for now. It is a very small map, and I will need to rework the checkpoint path for it.
I also added another Checkpoint map some time later:
Contact Night
It takes a long time to add a playable Checkpoint gamemode to a map which doesn't come with one. Someday I hope to get all the night maps playable on Checkpoint, but I have some ideas for a couple of plugins I want to write first. These will make my job much easier, and also make it simpler to tweak things later.