Isn't crit-glitch chance higher with 9 than 8? 1sec, grabbing anydice.com... 8 dice have ~0.11% chance at 5+ ones and no hits, 9 dice 0.13%. 7 dice are 0.41% at 4+ ones, 10 are at 0.03% for 6+ ones.
If you want to easily check yourself:
output [lowest of 1 and [highest of 0 and (7d{0:3, 1:1, -100: 2}-3)]]
output [lowest of 1 and [highest of 0 and (8d{0:3, 1:1, -100: 2}-4)]]
output [lowest of 1 and [highest of 0 and (9d{0:3, 1:1, -100: 2}-4)]]
output [lowest of 1 and [highest of 0 and (10d{0:3, 1:1, -100: 2}-5)]]
Oh wait. Extended. Right. Yeah, then go for higher counts.