In theory, there was nothing actually changed in the Steam version, so yes. However, I obviously do not have the Steam version to test it with.
Thanks for your response. I just found this while searching around (on the nraas forums this time), does it seem plausible?
"There are no game related issues caused by the core version mismatch provided you are actually on 1.66, 1.67, or 1.69 and using a Core Mod designed for any of these. It doesn't matter whether you are running 1.67 (Origin/disc), 1.67 (Steam), or 1.69, the game files are exactly the same except for the final build number which is what the mismatch error is reporting on.
The Feb 2017 update to Awesome was indeed for 1.69 compatibility, all it does is get rid of the core version mismatch error for those on that patch. I don't think the same was ever done for the Steam version.
As long as you are certain that you are not really running a Core Mod designed for an earlier than 1.66 patch level (so that's 1.63 and prior), it is safe to dismiss the version mismatch warning and play on. The tricky part is that when the game minimizes to the task bar instead of displaying the error, some players find that they have no way to bring it back up again and dismiss the warning so the mod becomes unusable for them."
The post was from 2017 so not sure how valid it is (if it is)