There are many ways to impact engagement.
Rollers: 14.5mm have a lower engagement vs. 15.6mm rollers will give you a higher engagement
Primary Spring: a spring with a Y-W-Y (45/128) with a 45kg preload will engage higher than a P-P-P (30/129) with a 30kg preload.
Engagement springs can increase preload: These shims range from 20thou to 60/70/80thou depending on your needs. It also should be noted that when you add a shim it will also effect total force.
HH's, HC's also have some adjustability for engagement, but the best way is to do it with springs...
--Buster696--