This won't apply in future large updates to SRB2, but in 2.2 backwards as Sonic when you are standing at the top of a tall ledge with a badnik below you, you can leap down and thok at the last second to combine the thok's horizontal speed with vertical height. It's a tricky, advanced technique that takes a bit of practice to pull off but is very rewarding when you do.
Back when the Multi-thok was still Sonic's ability, you could even chain this multiple times in a single jump. However, newer versions of SRB2 (Starting with 2.0 IIRC?) removed the Multi-thok from Sonic.