I haven’t tried Steve’s protocol yet. But I’ve read his book and I’m implementing some of his stuff into my training.
For finger strength I do just normal max hangs:
6 sets of 10s hangs with 2-3min rest in between on a 20mm edge with as much weight added so that I can just about finish the last set with good form.
Pretty simple but highly effective (for me at least). Went from 7c to 8b in a year