All good. The cap screws I used have a countersink angle of 82°. I found a countersink drill bit with a 82° point angle. Tapped out just enough material from the fans so that the top of each cap screw sits flush with fan frame. This will allow you to close the top panel.

• Countersunk Head Cap Screws [6-32 x 3/4" for EK AIO Rad + nf-a12x15]
  • Amazon Link
    • No countersink angle specified but I believe those are 82°.
• 82-degree point countersink drill bit
  • Amazon Link

Top fans do not move once mounted. The nf-a12x25 between the rad and psu is wedged in there pretty good.