I think we discussed this before. What if instead of the health and ammo dispenser, give the engineer a "Bacta Wave Emitter" or "Power Cell Recharge" powerup. I've looked at the assets and have been experimenting with this in game. I can never get the health to regain instantly. It's always within a certain time or not at all.
Once I figure this out I'll disable the effect on owner (No more engineers healing themselves)
100-200 HP given to a maximum of 10 people each time this powerup is used
No animation will be used when this is activated
All effected droid players will be given a short electric effect attached to the hip
All effected organic player will be given a short bacta mist effect (Similar to bothan spy buff)