Title. I think the shield regen is an interesting ability, but I also think it should be an option for the utility slot as well, for people that don't necessarily want C4. If shield regen could be used in the ability slot OR the utility slot(but not both), shield regen would be a more interesting option.
I would agree with that however, then you could be healing allies health AND shields at the same time. I think they gave it the ability slot so it would only be used for more support roles instead of always going lone wolf and being able to heal back to 100% in a few seconds.
You can heal allies and regen shields at the same time. Healing Grenades. They even just got buffed! And if you want to heal yourself and regen your shields solo without giving up Revive/Frag Grenades, you can carry Medkits I guess.
health regen is mobile (you always have it) but needs recharging after some usage shield regen may be static as a deployable but basically is unlimited to deploy and always active. i think that is a good tradeoff