Don't think any of the train station checkpoints are loaded before getting the first one in it. I tried for a while and couldn't find any. Sorry about not responiding in pms. My account is still considered too new to message people.

What is required for a launch to work? Like the general steps.

I don't know if there is a warp to the end of District 2 since the warps seem to be more of a way to move vertically as opposed to horizontally.

Can't reply since account is too new but to answer the freezing question: I have bound my jump to right trigger and slide to right bumper. Even if you rebind moves, the game still likes its original assignment so crystallize is on right trigger initially so the game keeps doing jump and crystallize once you've obtained it. There is no advantage to freezing things. Look forward to that teleport run you have!