TL;DRThe research and process for coal liqufraction is very complex; I think it should be made far more easy to access.
What ?Moving the research of coal liqufraction to be between oil processing and advanced oil, or as a side-branch from oil processing so you don't have to get it for advanced oil. It should also only cost red and green science to get.
Also removal of the heavy oil requirement, or having 'crude' coal liqufaction that doesn't need heavy oil.
Why ?While oil wells are infinate, if slow at the end, it is possible to spawn in an area without oil. Thus making it impossible to progress. This change would prevent a map being 'unplayable' by allowing players to use coal, inefficently, instead. Either until they've managed to research enough to conquer territory to find some oil wells. (The tank requires blue science, as does the better armours.)
Having just spent the past two hours creeping around biter nests trying to find oil, with a large smelting area already set up and some trains running... I don't want to abandon the map but without oil it can progress, so... An alternative seems like a good suggestion!
Thank you for reading.