Hello!
My suggestions:
- Rocket fuel, Nuclear fuel - make them not produce ash. Also with Plutonium Energy by JohnTheCoolingFan mod there is Plutonium fuel, make it also not produce ash.
- Hot metals by cackling.fiend: make bricks from ash come out hot (with hot metals mod and with brick option on);
- Mods by brevven: there are a lot of mods made by brevven that add new types of ore. Like lead, tin, zirconium etc. Can you make compatibility and modify ash separation recipe to include different types of ore, based on combination of mods installed? Like in Py, ash separation outputs not just iron ore and coal dust.
- Silica & Silicon by brevven: there is razograss plant that is used to get silica on gleba. It is used as a fuel and should output "razorgras ash", and a recipe to turn "razorgras ash" into silica (dryed razorglass recipe). Problem is that with your mod spent result for razorgrass is ash insted of "razorgras ash", so there is no way to obtain the former. Repacing "razorgras ash" with ash will bring balance issues, so i suggest to leave "razorgras ash" as spent result for razorglass in dryed razorglass recipe.

Tested ash with AAI industry.
There is Processed fuel item and fuel processor building. Any chemical fuel can be processed into processed fuel. Processed fuel does't leave ash as spent result for some reason. I think it should, to preserve ash complexity (without ash from processed fuel you will bring fuel into fuel processor, get ash from it at fuel processor and then never consider ash output again).
Extra ash imho is no concern: you can burn coal in fuel processor to get both ash and processed fuel, then burn processed fuel to get ash again. But ash from processed fuel is not in 1-to-1 ratio with coal input. More like 1 extra ash from every 2-3 coal (for different fuel ratio depends on fuel value).

Burner inserter.
There is reason in Py that burner inserters don't consume fuel and are renamed into mechanical inserter. You need an extra inserter for every burner inserter to remove ash from it and this is why burner inserters with ash are better be skiped asap.
Problem is exaggerated with AAI industry mod with its extended burner phase.
To preserve pleasant experience with ash I suggest to make same changes with burner inserters as in Py mod.

Hi there, I was pointed to this thread recently.

I've made a single update in Silica & Silicon's data-final-fixes to change dried razorgrass burnt result back to razorgrass ash to keep better compatibility. (I have not addressed any other ash separation balance on my end for now)

Its a good start, thank you!