The Obelisk could emit a Redstone Signal upon reaching a certain amount of XP
This would be individual, for example: if I had 10 obelisks, I would define the quantity of each one individually!

Sorry for the late reply.
Can you give me some use cases where the redstone output would be an improvement?
I don't get it, why would you have 10 Obelisk's The only thing that comes into mind is each on a different mobfarm... but then you could just simply plonk it down insert an pick it up ( to store in enderchest for example).

I could as the server owner, I thought about creating dungeons and some things in my main city that used experience.
To create a balance at the players level.

But your Obelisk is really pretty, so instead of creating a plugin or mod, I thought if your mod had that, it would be more immersive within the game!

My server is a Mediaval RPG.
I wanted, for example, to release a specific area on the map using experience.
But it would be a larger amount of XP so that all players would have to contribute to one day unlock that area.

But if the Obelisks didn't have individual settings, this wouldn't be possible!
Because if there were multiple areas with the Obelisk, they would all have the same amount of XP required to emit the redstone signal to open the door/gate.

But sometimes one location can be better than another in DROP rate and etc. And as you said, there are mob farms too!
And I think players could think of a lot of other things too!

This area would be released through redstone, upon reaching the required XP.

I just thought about a situation like this too, that it would be nice if the Obelisk had an option to enable XP consumption over time.
For example, every second the obelisk would consume X number of XP, causing players to always have to donate XP to gain access to the area.

If you approve of any of the ideas mentioned here, let me know so I can edit the main POST so it's clear and safe for anyone wanting to ask a similar question!