Update for future viewers/purposes:
I molded Palau Power fit MP 285 with UPZ RC10 (299mm). I was riding them for 3 hours yesterday and it's good fit.
Still, it's pretty tight and I had to unzip them every run. But I think after few rides it would be perfect.
I will try to mold them with my Sidas footbeds (I have flat feet) in a few days. So yeah, downfitting in my case worked out, even though it seemed impossible at first. Thanks @daveo, @JRAZZ and rest of you.