my cousin owns a very successful tow company.
I don't know what his current practice is but when I was around his shop
he would always have a big bottle of ATF mix on his equipment
he didn't use it all the time but when he needed high power output in it went.
filtered old motor oil is also a popular fuel alternative and or additive
and with a higher BTU and higher lubrosity it has definitely got positive aspects.
and you do need to filter it
this is a pretty good article on filtering and mixing and it would pertain to ATF as well
https://usfiltermaxx.com/en/content/9-make-black-diesel