Reyna is awesome, but I think her Shield Booster ability’s targeting needs to be tweaked a bit. If my teammate actively maneuvering the most frustration goes from “dud” when you missed your target. Ability momentarily deactivates and you need to recast it and try to lock again. I think targeting mode should stay until you lock and successfully hit the target and only right-click will be used for cancel.
It takes practice but eventually you can really thread the needle and hit your target. I still miss from time to time but I find a combination of communication, aiming first then using the skill and leading the target will help to land it.
You should change your skill activation to instant. No more lock on needed. It does make it harder to hit a specific hero if your team is bunched up, but you will almost always land a shield to save yourself.
I prefer Quick, which lets you hold it and release the button when you want to launch it.
Instant might be better in this situation, but I find Quick has more tactical advantages than Instant in most situations.