It might be fun to add in custom abilities that for example make you jump 2x higher for 10 seconds if you activate it (by right clicking an item or something). It would of course be unfair if this were to be used at /warp pvp so if this is going to get added I suggest that you disable it when you are combat tagged.
we were going to add double jump as an ability for dragon levels, it might be added just depends on the demand for it