Sorry for the delayed answers, guys. I had to retrieve the bike from workshop I left it at, and then I finally broke that stock flimsy belt drive train it has, the rear sprocket got deformed and developed a huge play around the axle, so I guess it's made of some very cheap material.
I'm now adamant on buying Gates drive train. I just need to solve a problem of selecting belt of a proper length, and also ensuring chainline will be straight. Not sure how to approach both problems yet.