Any chance we can get processed fuel from AAI added to the configuration settings for preferred fuels under the 'chemical' category? It already shows in vehicle fuel. Not exactly game breaking, just a little inconvienient to have to keep converting from coal to processed fuel to work stuff out.
Cheers.

Hello, normally it should every fuel that can be used as chemical fuel. I think I might know why you ran into this issue though, I'll have to double-check though before I can be sure. Thanks for letting me know though!

Came here to make the same complaint. Here's how the choices look when you are picking fuel for an individual recipe:
https://i.imgur.com/TvzOMoT.png
and this is how it looks when you're trying to set your preferred fuel. Notice the lack of the "processed fuel" that I had selected in the individual selector:
https://i.imgur.com/Rhzt2is.png

Yeah this is complicated. The processed fuel has its own category, and the machines accept both the chemical and he processed fuel category. The fuel doesn't show up in settings because it is not a chemical fuel, it's alone in its own category, and categories with only one member aren't shown as there is no choice to make.

There are probably a few solutions to this, but none I thought of thus far are very practical. The brute force one is to also offer every viable combination of fuel categories in preferences, but that's obviously a combinatoric explosion, and not worth it to solve this single case imo. Another solution is to hardcode the processed fuel to be part of chemical fuel, but that probably causes tons of exceptions to be required elsewhere, and I don't like hardcoding things from specific mods. Soo yeah not really sure what to do about this. If anyone has a good idea, please let me know.

What I'm wondering is why chemical fuel gets priority over processed fuel. If I have coal selected as my preferred chemical fuel and the processed fuel is the preferred processed fuel on account of it being the only processed fuel, why does the planner pick the chemical fuel? What makes it pick one category of fuel over another, preferentially? Maybe letting us pick/order preferred fuel category would solve the issue, if we'd be able to put processed fuel above chemical?

That's not a bad idea actually. Right now it just picks the first one by the internal ordering. Having an option to order the categories would help with this for sure. The UI for that would be kinda clunky, but that's fine. I put it on the to do list, thanks!