Hi darkfrei, I apologize, but I’m going to have to say “will not implement” on this for a couple reasons.
First and foremost, as per my current understanding of the original mod requester’s intents, adding non-vanilla items and fluids would go out of scope of what they wanted. They had said they wanted something simple to take care of excess wood and when pointed to a few existing mods (that have these intermediary steps, like Wood Gasification), they said they did not want something that produced non-vanilla items that required further processing to deal with.
Second, while I have admittedly not done deep diving research on the real world methods the mod requester linked me to and described, based on my current knowledge, something like tree sap does not appear to be an actual product/by product/intermediary step to these processes. I’ll only add in things that are known or realistically expected to comes from these processes, provided they do not conflict with rule 1, no non-vanilla items & fluids. Coal might be, but I’ll have to look into it.