I have noticed that Beam NG is really laggy even though i have enough to run on normal or low. Should i take the risk with downgrading the version from steam (i bought it from steam).
Don't downgrade it, the previous version wasn't any less laggy, it definitely had much longer loading times. Maybe play on lowest settings, idk.
Some maps requires more from your PC. Same as with vehicles. The game has been optimized over the years, a downgrade would most likely have no difference or make it worse. What are your PC specs?