Looks good to me. Surely you've learned it takes a keen focus to hit a desired count per length but it also takes repetition, lots of repetition. How many rounds of this set did you manage? I'm also sure you'll find that with repeated practice of key sets like this one you soon begin to dial in to your ability to cycle through your personal range count and do so at will.
Maybe also practice multiple repeats at the same count ie.
3 rounds of
4x25 @ 17spl
4x25 @ 18spl
4x25 @ 19spl...
When you become keenly aware of how to manage each count then maybe increase distance a bit, say
2x50 @ 17spl
2x50 @ 18spl and so on...
If this begins to feel good you can incorporate your ability to cycle through each count within the same repeats as in the "stroke calibration" set.
Do these exercises in reverse order too and really hone in on your skills.
Thanks for sharing and good luck in your practice.
Never give up that sense of experiment.
P.S. Search out Terry's practice sets in this regard, in fact ALL; they're invaluable