Mch needs more

[Rongway]

Just doing some quick napkin math with potency values, and Spread spam is lowest aoe priority even counting heat and subsequent autocrossbow.

It's Bio (360/GCD) -> BS Auto (300) -> Flamethrower (250) -> Spread Spam (207)

Here are the per-second values:

Bioblaster: 360p / 2.5s = 144p/s
Autocrossbow: 180p / 1.5s = 120p/s
Flamethrower: 100p/s (Flamethrower ticks 1tick/s instead of the usual 1tick/3s)
Spread Shot: 180p /2.5s = 72p/s

even counting heat

Heat doesn't affect AoE actions, so you only have to worry about Autocrossbow being on a minimal GCD.