I'm not understanding something here:
1) why would I warp an exosuit? I'm still limited to six total, yes?
2) how do I "spend" an exosuit to pay the warp tile back? Am I now limited to five exosuits?
It gives you a powered up one, so if you couldn't power a needed one up in a round you can still get one.
You always have 6 available. To pay it back you must give up a powered up unused suit back to your supply. The 6 amount never changes.