I don't know if there's a right answer to your question, but, IME my best times on short climbs of 7-10% are produced with cadence 95 & above. This past spring I did a 4 week ftp builder that also increased my ability to sustain high cadence at high watts. The results was evident on competitive group rides when I was able to pedal high cadence seated up climbs and pass others that were standing mashing their way up. I was impressed results considering it was a canned Zwift ftp build program. I didn't cheat the program & fully committed to it... it was a lot of effort but it paid off.