Definitely Tap/Hold
What I'd also love to make her a bit less of a glass cannon would be having a weaker version of the inactive buff active for example whenever you're buffing damage it could also give you a damage reduction that caps at say 50% and vice versa with the DR active a damage buff with a certain fraction of the damage buff.
This could also be an augment that just gives you half benefit of each at all times (or slightly more so it warrants a mod slot)