..and solved! I think the plate pull spring got mis-aligned or something..anyway I took the chance to spend an afternoon with my trigger, completely disassembling it, removing silicon oil excess (from where I had no other lubricant), checked trigger sensitivity, re-greased, sanded off some smudges in the impact plate etc. etc. etc.
Not only the trigger works, but I had the chance to work on the bolt and now it's working wonders. For the sake of getting the feeling of this rifle back, I put the PCS valve at 50% and reinstalled the stock striker spring.
The 29 round magazine I fired was a pleasure to the eyes and ears. I got approximately 27 hits on a coke can at 35 meters, from a standing unsupported position. I can notice that the spacers I put keep the entire barrel much more firm during the gas output..plus cleaning the barrel, aligning the scope to the horizon, and mostly the long magazine being SO much more consistent (will never use the short stock one again, it's probably the most inconsistent magazine of ALL gas rifles) turned it into a beastzor.
Still, this mofertucker shoots hot as hell, judging from the time between the bang and the ding.
..AAAND HE'S BACK!