I figured out how to pull this off every time from almost the very start. So might as well share this info since many always end up with a kit or more none glitched. ie. Krogan Shaman.
Going to use Adept class as an example;
- Spec your glitchable characters for Adept class; which is Volus, Krogan, Batarian, & Collector (don't worry about some leftover points).
- Get them between level 16-18 (I usually start as soon as I hit 16).
- Level up with another non-glitchable character (from N7 character kit and earlier release kits).
- Spend the extra points after match & level up on all glitchable characters for Adept class (make sure you're host and turn it to bronze it players aren't giving you the time to do this - this resets timer then scares them away).
- You should now have at least one character who is maxed out at level 17 (in Adept class, it's always the Collector Adept for me. Though I also start with speccing him first too). So I usually continue with that maxed out kit to level up for the next match.
- After another match & level up, spend more points for remaining glitchable kits. But now you may want to exist mp and back at title screen, then back to starting another fresh lobby. As somewhere after this, some kits may end up in the negatives. But don't worry if this happens if you decide to still go on and still have more levels to gain afterwards. Because exiting back to the title screen fixes this (just don't enter their power speccing screen until after another level up, or it'll show them in the negatives. aka. tricking you into believing title screen trick didn't fix issue).
That's it. Have fun. And see you in pug land all buff and glitched.