Hi again,
sorry for not replying sooner but I've been away on business and couldn't do anything about my situation in the meantime. While I've been on the road I thought about changing the screws with some whose winding goes all the way along its shaft so I can apply some more pressure.
While I don't constantly tinker with hardware, I believe myself to be technically and manually proficient (I have been repairing my motor-bike on my own, after all
). It's also not the first time I've done something like this. Half a year ago I put together a PC for my parents-in-law and the cooler needed its own backplate too, I believe it was a Thermaltake though.
I'll post again after I've done some further testing.