The recipes from chunks to crystals don't require any acid whatsoever, unlike Angel's Refining crystal recipes. Is this intentional? I see a commented "--Acid" in the code where the acid is supposed to be.

Seconded. I find it weird that the additional ores don't require acids and was going to comment about this. Somehow only noticed this recently. As for what acids to use, the acids that Angel uses correspond to the kind of waste water produced from the flotation process (e.g: saphirite flotation produces sulfuric waste water, so it uses sulfuric acid in the chemical refining stage). This is only a suggestion of course, so it doesn't have to be like that.

I was under the impression that this was fixed, ill see what I can do about it tonight.

Ok, i have found the issue, i am patching it now, the setting was linked to the angels infinite ores mod, and the null case was not built...

There has been an unintended side effect to this patch: this mod's infinite ores no longer obey the "Adds fluid requirement to infinite ores" setting from Angel's Infinite Ores. If the setting is turned off, the ores still have a fluid requirement. I think all you have to do is change line 86 of data-updates.lua from

if mods["angelsinfiniteores"] then

to

if mods["angelsinfiniteores"] and settings.startup["angels-enablefluidreq"].value then

On an unrelated note, where is MadClown? You're the only one I've seen that is maintaining this mod.

Ah, I will fix that asap...
Madclown is still around, but now has a job that is taking more time from him than he expected. I hope he finds the time to come back.