My approach is usually to get the spur fully charged before approaching an enemy, release it, and then keep shooting out level 2 shots for the remainder of the battle. I don't actually have any analysis on whether or not this is the best strategy, or what really does the most "damage per second," but this is just what always felt right to me.
Also yeah, even though the turbocharge does technically speed it up, it's kind of hard to tell unless you actually time it.
I've never heard anyone comment about this tip I mentioned in 2018:
"Did you know? If you charge the laser and access the inventory screen to switch weapons, it will maintain its charge until you open the inventory screen and switch back. "
This way if you wanted to use another weapon for your primary, you can charge the Spur ahead of time to lvl 3 and then switch to another weapon. Spam your other weapon all you want... and when the need arises, line up your attack, open the menu and switch to instantly unleash the full power of the Spur!
I immediately started wondering how much that could save on the counter during hell running but I'm not sure there'd actually be much use for it? There isn't a lot of time to even charge up properly in the first place, aside from the big gaps before and in-between Ballos forms that basically give a free charge each time anyway, and it still means foregoing the advantages from using the Snake.