Just an update, similar method worked for me yesterday, managed to finish the instance by running till about half of the platform when initially getting on the platform, then letting it complete an up-and-down cycle and move forward a tiny step, another cycle, another tiny step...
Hopping didn't work for me, everytime I press jump on the platform, I get instantly teleported under it and stuck.
Thanks for the help anyway, now I just need to figure out where to get Key to Arcatraz for [Outland Dungeon Hero] :/