This doesn't actually help you, because overloading propulsion only increases your speed while moving not attacking, in other words, during the run through cells towards an enemy, for example, not while you're already adjacent to the enemy you want to attack. When you attack you just make an attack with whatever speed and momentum you already have at that point.
If i have 1 momentum and 20 speed, and i overload flight units to reach a faster speed of 8, then my melee bonus goes higher, even without moving, as shown by both Cogmind's stats and my weapons'.
An automatic toggle isn't really feasible, since it's not known when your intent is to attack.
Correct me if i'm wrong, but doesn't the auto-threads feature already detect attack intent?
Also remember to use the CYCLE button (or hotkey) to quickly overload all your propulsion at once if and when you are going to approach a target.
Clicking the CYCLE button doesn't overload propulsion, only swaps it between active/inactive.
At least i don't think so? I'm certain i tried several times in my last run to toggle overloading like this, and it didn't do anything?
The reason i checked was because i thought it did overload, so either i missed it during that run, or it was accidentally removed.
Edit: I double-checked a recording, and clicking CYCLE turned my flight units from all active to all inactive. They briefly go yellow, but that's it.
But don't expect that staying in an "overloaded" state means anything after you've already engaged and aren't actually moving anymore (this is also why your momentum drops as soon as you do anything over than move).
Given what you're saying, it sort of feels like i'm going to cause a nerf to flight/hover melee, but Reaction Control Systems give 1 momentum even if you aren't moving. And those are the best way to dodge stuff while flying/hovering.
I don't know about other players, but they're usually my first option for additional evasion, meaning i'll usually have one while fighting on flight melee.
Cog-Minder also agrees with me about the benefits of overloading propulsion. The attached screenshot is for fighting one of the most powerful bots with melee weapons while stationary with a Reaction Control System, and the only difference between the two is speed.