So I consulted DBA support, sent them recent photos of my discs (since my problem with brakes fade was still very much apparent) and they basically told me that hoho, sucks to be me but it that doesn't really seem to be proper pad film on those discs, more like decaying corpse of severely overheated pads...
It also turns out that DBA RP pads are not offered in Europe unfortunately. However mad respects to DBA support because instead of making up some bullsh*t to sell me more of their products, they actually plain recommended me DS2500 or DS3000 pads. So I guess I'll just try those instead c: