Yes, the Shop Manual and Owner's/Operators Manual are not very good with instructions for setting valve clearances. There is no statement about adjusting with a running engine or with the engine off. Running the engine for 30 minutes before adjusting is stated.
I was taught to adjust with the engine running - ugh.
I have seen photos of valve covers with the tops cut open to contain the splatter when adjusting a running engine.
The "static" methods on a warmed-up engine are cleaner, faster, easier, and most likely more accurate.
