Why does nobody seem to use Smart Moving on their servers?
Look at this stuff, try it, it's pretty much the best. Enables stuff like climbing up ledges (at waist height fairly fast, slowly if it's at head height), charged jumps up to double normal height allowing you to grab ledges
four blocks above you and haul yourself up (slowly), nerfs sprinting so you can't just sprint forever through the night and be safe so long as you have food to eat afterwards, changes ladder climbing and is stupidly configurable to the point where I haven't even been able to be bothered to dig through all the config options and see what can be done
(there is a little bit at the bottom of the config file on servers to force overriding client configs, which you should probably enable so people can't turn on free climbing and just spider over any obstacle forever)
Just holy stuff use it it has a bukkit server component or forge if you like inficraft and redpower on your servers and syncs nicely with the client side