I just tried my first bottle of Legacy's 110, jury is still out for me.
You may have your own methodology down, but I've dialed in my 35mm film/dev testing to learn a lot from one roll of film.
I create a small set with textured white (styrofoam packing piece), pure white, grays, an actual gray card, textured shadows (a very dark flannel shirt) and a solid black backdrop. I light it with a 4-bank biax flo through diffusion (about any constant light source would work) and I leave everything unmoved until I'm done testing.
I'll take a spot reading (you can use a DSLR set to spot and a zoom) and see how the setup works zone-system wise, and base exposures on that - but I keep notes of highlight, mid gray, and shadow readings, and also compare the mid gray to a handheld spot reading.
I shoot the standard exposure tests - usually 4 frames is plenty. Just tested HP5+ at 200, 250, 320, and 400. And then did some push tests at 800 and 1600.
But... in my darkroom (or changing bag) I make a bunch of strips of blue painter's tape, about 1/2" long by 1/8" wide, and fold a small tab on the end of each - I stick those on a small plastic box with the tabs hanging out so I can find 'em in the dark.
I shoot my bracket of 4, and take the camera in the darkroom. Advance one frame, open the back, stick a tape-strip on that frame, close the back, and advance one more frame. If I do that 4 times, I've shot under 24 frames. So I have four sets of brackets. (With a 36 roll I'll do 6 sets of four, and maybe do some push tests). Every four frames, there's a blank frame with a tab of tape on it.
When the roll is full - back in the dark, I open the camera, and cut the film at each tape strip by feel (that will be about the center of a blank frame). I peel the tape off to avoid any junk getting in the developer. I put each 5-frame strip in an empty film vial, and load one onto a reel (4-5 frames is fine for plastic and metal reels - for metal, just sort of work it into the middle of the reel, don't use the Hughes hooks!)
Then I choose 4 different processing times, keep the temps and agitation the same, and process the strips one at a time. I'll re-use the dev twice since 4-5 frames won't exhaust it like a whole roll would. Could probably use the same tank of dev for everything, but maybe it oxidizes?? It's cheap.
After I make contact sheets and maybe do some 5x7 test prints, I'll still have two more strips that I can use to play with agitation or temp or whatever differences - these can answer questions that come up when you see your initial tests.
You can learn about everything practical to know about a film & dev combo with one roll of film and a couple batches of dev - fixer will be good all the way through the test.
I about guarantee you you will be pretty much an expert on your film & dev combo, what works, what doesn't, how far to push and what dev. times are best for which ISO rating you give - with just a couple hours of (very interesting and fun) work... and ONE ROLL of film.
REGARDING AGITATION - my experience says use more time vs. more agitation if you want a smoother highlight range. Agitation can just kick the teeth of your highs... for an 8 min. tank time, I might do a few gentle swirls every 2-3 minutes... but right now I'm experimenting with 400 and 3200 films.
