Couple ideas to cut micro on dread upgrades
I think the dread instant heal 'upgrade' should auto apply when the dread is about to die. However, to not make it OP, maybe it should only heal 50% of the max health. This way the annoying micro controlling experience of trying to hit the upgrade button at the optimal moment in middle of a battle would go away. The button wouldn't even be there, but if you haven't selected any of the (other) upgrades on a leveled up dread, and it's about to hit 0 HP, it would consume the level up to auto heal.
Another way to cut a bit of micro management on the dread upgrades would be to make the upgrades only apply after the dread has not engaged in combat for 10 seconds or so. The upgrade could be chosen during combat, but it would only get enabled after the dread hasn't taken (or caused?) damage for a while. This way players wouldn't need to worry about clicking a dread upgrade asap. Additionally this would add a bit of strategic depth in the form of having to decide whether to keep the dread in the battle, or to withdraw it to apply the upgrade.