Dragoons: I'm not sure how close the Jump skill here is to the default Jump skill in Heroes, but testing with it on my server, I could NEVER cause myself to take falling damage whilst landing on the same level from which I leapt. It also felt like the default jump was a bit more robust, which I would imagine would increase the fall damage I should take, but that wasn't the case. The only time I would take fall damage would be if I fell past my launching point far enough to take normal fall damage, even if I had careful walked off of the cliff. In Herocraft right now I take significant falling damage around 80% of the times I Minecraft jump>Heroes jump, and even just using the Heroes jump alone I tend to take fall damage more often than not, testing on a flat surface. This fall damage is generally up to 25% of my health and takes rather large chunks out of full set of iron armor.
Improved Chat Mod: It seems that there's a plugin on the server that prevents you from typing a quick fifth message after typing four messages in quick succession. I assume this is to somewhat curb fast chat spamming. Unfortunately this plugin seems to include any message that goes into the chat box as part of those four messages. Checking your health, mana, hero level, and using skills through Improved Chat Mod seem to all fall under the jurisdiction of this plugin. So if during battle you happen to use four skills in quick succession, you will be essentially silenced from using any chat based skills until you stop trying to use them for a certain (untested) amount of time.