As someone who has played OITC for more then 3 years, there was a lot of glitches that I knew of such as: (BTW keep in mind I haven't played brlns in 2 years so.. IDK if these were fixed)
In maps such as the city with the bridge on one side with the vines, and the buildings on the side with buses and cars in the road... there lots of stair/windows, some glass blocks, especially behind the bridge with the vines made of like stone brick, there was some glass block which you could click and break, and then you could go like 1000 blocks away from the actual map, it was kinda crazy, then you would get to huge grass area where you could crouch at the edge of the void, so If anyone teleports to you, they fall in the void. This was a super OP strat to farm wins.... Also, the map that's sort of like a garage terminal thing, made with lots of green/brown terracotta, there was this trapdoor which would allow you to escape the map, and do the same void strat... There were so many more maps with glitch exploits, but some of them that I can't remember any glitch exploits in was the candyland and the frozen Ice map, with the houses and Icicles.