Edit: Looks to be resolved in 0.4.5! Thanks!
I was wondering where my oil barrels were, haha!
Once the "Disable oil recipes" option has been set, it can't be disabled because data.lua is checking if the option exists instead of its value:
The line in data.lua:
if settings.startup["disable-oil-recipes"] then
should be:
if settings.startup["disable-oil-recipes"] ~= nil and settings.startup["disable-oil-recipes"].value then