I hate biasing!

Not knowing what the screw looks like, but I bet it is hidden in some way.
One useful way to make it easier is to have a sleeve around the screwdriver shaft, which would keep the screwdriver head ON the screw.
A thin barrel. you could even make it out of paper. just tape it around the shaft, so the head is just even with the bottom edge of the blade.
If it works, perhaps something stiffer for more permanence around the shaft.

I have used that sort ot addition when screws are awkward to reach.
Keeps the driver on target and easier to work with.

+1
We used to put heat-shrink on all our screwdrivers for that exact reason back in the day in the service dept. It also avoided shorting against the chassis if there were voltages present.

I own a Ref 150 SE and have to bias 8 KT-150 tubes.  Can't say I love manual biasing either.  

FWIW, I think ARC just came out with Ref 160 mono block amps that have an auto bias circuit.  No more fuss or mess.  

Interesting change of philosophy at ARC. I recall many years ago a conversation I had with either Lenard or Kal about the benefits of manual biasing.  One or both of them told me that ARC thought that an auto biasing circuit would in someway degrade the purity of the signal path.  Perhaps ARC's R&D folks figured out a way to insert an auto bias circuit that is more benign to the circuit, …  or maybe the original philosophy was just bogus. Dunno. 

Whatever the reason, I surmise that ARC's original philosophy at the time was sincere. I gotta believe that the marginal cost increase associated with adding auto biasing components was de minimis when compared to the MRSP of the amp.

Regards,   

BIF

Hey Liz, … is that you.  Are you back??  I've been off the Gon for some time.  If it's you, glad to see you posting again.  :)  BIF

I now own the Carver Raven 350 Tube amps. Though the adjustment is on the back and the meter is in the front. One adjustment and all tubes are set.

ozzy