I was noticing a few turrets upgrading very fast.
It looks like the default "Kills to Next Quality" is set to 1.
Is that a multiplication, or a hard set number?
Could it be turned to a scale? So it takes more kills per level?
Also, does it count for Astroids?
Thank you!

Its user adjustable, every time it gets those kills, it will upgrade.
As to scaling, that would mean I would need to guess the next quality level.
The way I have this setup is to be agnostic as possible to maximize mod compatibility.
Someone will be adding an elebenty kajillion quality level mod, and this as it stand can handle that.
Adding logarithmic would be fun, since technically you can set up a kill field and harvest legendary turrets for their goodies, but that I leave as a responsibility to the user.
As to asteroids, I haven't gotten a chance to check. It works on the turret kill count.

bug report : 【Kills to Next Quality】 count doest work.
once a turret up grade to next quality 【Kills to Next Quality】 return to 1

bug report : 【Kills to Next Quality】 count doest work.
once a turret up grade to next quality 【Kills to Next Quality】 return to 1

Ive undone the kill transfers on promotions to fix this in theory
I tried modulo but it seemed to ignore any other commands
Do you have a suggestion on what operator can be used?

i mean. if i set 【Kills to Next Quality】to 10
LV1 kill 10 >> LV2
LV2 kill 1 > LV3
LV3 kill 1 > LV 4

You could configure it as 'kills to max quality level' then simply check the number of quality levels in the game. Then apply them as horizontal lines to a function that goes from 0 to 1, with the lines being at n/nmax, with n being the next level, and nmax is the highest quality level.
The Y axis is kill/maxkill so the entire function is normalized to be in the 0 to 1 range.

+1