Thank you so much!

Okay, I posted a new XP table mod for you. You can find it at: https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?edit=true&id=3021270043

It requires this mod and will overwrite the hero XP table and nothing else.

Either would be very kind of you. I don't really know how to mod at all so if it's getting me to import it (not even sure how to do that) you'd have to explain how to do it I'm afraid.

Okay, so if I remember it right, this mod effectively doubles XP requirements to level a hero. So a level 15 hero at 2x hero points would be at least as powerful as a level 30 vanilla hero, and likely stronger due to (albeit limited) class abilities and mechanics.
I have personally reached level 30 in games with double XP requirements in under 100 turns, but I did play heavily modded games with dramatically increased difficulty and spawn rates. This obviously wouldn't be the case for a normal game.

I could look at creating a version with normal XP gains if you can't import the mod and create a small personal mod-mod to set values you're comfortable at (which would offer the additional advantage of being able to change it without needing me in the future.)
The AI should be getting a percentage gain so they should be fine without edits.

I like the idea of this mod, but it's impossible with this mod to reach level 20 never mind 30 for human player heroes and leaders even on a large map with few AI players and lots of explicable locations, even if you string it out and wait for invasion events, buy off the AI with bribes to delay the final war. Highest I've managed is level 15 before the second AI player defeated the first and went to war with me and surrenderd after 10 turns of war a bit later. And that was managing to put off war until turn 200. And only one of my 21 heroes made level 15.

The XP needed per level should be reduced a fair bit. If that'd make AI heroes level too fast, reduce their XP bonus a bit.

Thanks for making this. Any chance of a version that doesn't require more experience to level?