I've measured the bevel angles on every wood carving tool that I have ever bought. A little device originally meant to measure the tip angles on drill bits.
All the carving knives are somewhere in between 12 and 15 degrees, total included bevel angle. To me, that means 6 degrees per side.
I used a geometry set protractor to draw 6 degree angles.
For a carving knife, lay the thing on the strop. Lift the spine of the blade about the thickness of a beer mat. Close enough.
Now for crooked/spoon knives, the setup is the reverse. The knife is stationary, the abrasive moves. Hold your arms to your sides and move from your knees, not from your elbows.
I use all kinds of cylinders for mandrels, from chain saw files and up to a tennis ball.
Yes, carving is tedious. Carvers understand what carvers are doing.