Hello. Sorry for not responding. Must have missed this one.
Besides @carstene1ns nobody of us has a PSP or PS Vita to do any testing and afaik c1 is not working on this anymore / has no time.
So is kinda on hiatus until some motivated developer (also from outside of our dev team) finds time to port it to the PSP. If you should know anyone who can help please tell them to contact us.