Yeah, her kit is already quite strong but needs some quality-of-life improvements for sure. Faster casting animations, longer ability durations, recasting Energy Vampire on multiple targets at once, etc. would make a big difference. It's an interesting niche being the only pure support frame in a game focused on killing masses of enemies as quickly as possible. Well of Life is what needs the most change.
What if, upon recasting or holding to cast WoL on a target (perhaps as an augment like mentioned), Trinity temporarily transfers that enemy's health to herself as overguard? Doing so would forfeit the ability's other effects for the caster (due to how overguard works) while providing them to allies in her vicinity based on her ability range. Damage dealt to that overguard amount would be transmitted to allies as health within Trinity's affinity range (not ability range) at a percentage rate based on her ability strength. That way, squad mates can go about their tasks without stopping to shoot a target for additional healing. If EV and WoL are cast on the same target, then energy would be restored instead of health at the same per-second rate based on ability strength, and the hold-to-cast version would provide overshields instead of overguard (benefiting Trinity as normal this time). This could ultimately restore more energy than EV alone. WoL would end when the overguard/overshield value is depleted, the caster manually deactivates the ability, or its duration expires. The extra health or shields would also expire, and damage dealt to them during that time frame would then be applied to the target enemy's health pretty much as it currently does.
That would make more synergy in her kit and add needed utility to her first ability.