When you bonemeal twisted or weeping vines, they grow exponentially; acting like scaffolding. This is insanely OP and can reach build-limit in a matter of seconds.
How to recreate
1. Place down weeping or twisting vines
2. Hold down right click with bonemeal in your hands
can confirm on windows 10 for 1.16.0.60. This was just changed on java edition to be a much more realistic, and bedrock needs to follow suit. Technically a parity issue atm.