People may pipe in here with more experience than I was "Speed increasing" (or at least "speed retaining"??) chemistry.
I can only add, you'd be wise to test whatever is recommended - your eye, lens, camera, choices will all affect exposure and how the negs react to the dev. Snip a few frames from a roll you feel is average. 4 frames or so will stay in a 35 reel without sliding out. Or suss out how much leader is blank with your given camera and add a couple inches to it.
When I do tests for important film, I **try** to resist running the rest of the film until at least I can make a contact sheet with a #2 or so filter. And then as long as the dev is in the tray, maybe cut a sheet of RC in half and make a couple 5x7's. I'm not as good at judging negs as I am prints, but looking for something that prints easily with a reasonable contrast filter is often worth the time.