Took her apart again to fix the one pin that didn't make contact without external pressure and to see if I could do something with the three bent springs (came with two, bent another when my puller snapped under the key into the spring when the key popped up; was mistaken last time when I said 3+2, it's 2+1).
What I did, try and bend the springs a little more into a normal shape, quite unsuccesful, but turning them around and fitting them so they bow towards the front made them *all* work again; one is now clicking on the way up as well as down, one is functionally indistinguishable from a straight one, and the other is a bit strange in that it works perfectly when you tap the key from any side except the front. So basically I could use two replacements, but I'm not feeling opening that beast yet again.
I fixed the connection between the membrane and the pcb by putting a cut-off ty-rib underneath the spongey rubber to prop the connecting end of the membrane up a little more; works perfectly.
And I fixed the F11 key not working by redrawing the relevant portion of the membrane with my refillable pencil, it was visually quite clear that it was 'burnt' beyond functioning; while I was at it I redrew any other funky-looking areas as well.
Protip: don't use 'pause-break' as testkey in aquakeytest, it'll report strangely on any keyboard; that really got me on this one, thought it was because of my membrane reworking that it only flashed sometimes and never held- not the case, it appears that the key will always send down and up immediately after even if you are still holding it down.
Also glued two of the snapped stabilisers back in place using superglue, it did take a few tries before I managed to reinsert them without breaking again.
One thing that's annoying me is the main enter key, it's sounds and feels different from the rest (though right-shift and space are also candidates for most awkward sounding&feeling button on the board) because it uses the only metal stabiliser on the board.. Will probably drop some grease on there to calm it down a bit.
This was after replacing the caps obviously, see previous post for that.
Funky little detail, the board (at least after capswap) takes quite a bit longer than any other I've tried to initialize when plugging in.. made me freak out a few times since during that time nothing registers ofcourse.