@Will Be Your Waifu For MMR
I did a quick test, and the level up tool tip seems to show the new values. The buff icon details do not seem to update and the actual value changes do not seem to actually change the resistances or dodging of allies. This was very quick and dirty so more investigation is probably needed. Although I tried using another mod that supposedly increased these same values and still did not see the changes being applied to a character.

The format of your mod description is really well kept, so cheers to that. However I have to say the range of leadership is not the only thing I find lackluster about it.

If you boost the elemental resistances, does it show it in-game?