So someone made a topic saying there's a glitch of the tone thinning out if you roll it above 8. It's very subtle, but it's there.
I got sick of marking my knob with permanent marker, so I did a semi permanent solution.
I basically took super glue, took off the tone knob carefully with the pry end of a hammer, and dabbed a few layers of it on the rim of the bottom of the tone knob.
After I formed a lump on the tone knob, I cut out a thin piece of plastic to glue slightly to the pick guard, right under where I want the piece of plastic to obstruct the knob from going past 8. The plastic I used was a simple soda cap ring cut into a small rectangle.
After that, I glued that to pick guard, and then turned the tone knob directly at 8.
After that, I line up the knob for the bump of super glue to be right beside and behind the piece of plastic.
Once I did that, I push it in far enough to float above the plastic piece but still have the glue lump to hit it when it goes to 8.
It's really useful if you want to roll up back to full tone really fast without having to gauge it at 8, which is hard if you need to do it quick.
The best part is that the process is easily reversible just by lifting up the tone know a little higher until it passes the plastic.
If you don't want that, then you can carefully chip off the plastic and glue on your tone knob as long as you didn't use too much.
I only suggest this to people who don't mind very slight alteration of their Variax. The solution isn't noticeable if you cut the plastic small enough to fit under the tone knob.