Text Mesh Pro add more sprites to asset

Hi,

I'm still new to unity and TMP, but I was wondering if there is a way to add more sprites to an existing TMP sprite asset.

I'm currently working on a game including hieroglyphics and I'm adding them by using having a sprite for each hieroglyphic I need. The problem is that I don't know yet which ones I need (there are more than 1000 hieroglyphs, so adding them all is not a solution).

The problem with simply creating a new sprite asset is that I'd lose the changes I made to the names, offsets etc.

I have tried updating the sprite image to contain more sprites, but the problem is that the sprite asset still only recognizes the inital number of sprites.

Is there a good solution for me?

With kind regards,
Ard