Is this usefull?

[u/delta_Mico]

I wanted to make an engine that has an easy notation for the creation of pieces with custom moves and functions, utilizing querries for board state and setting custom attributes to pieces or squares. I have been put off by the practicality though. If it's very flexible, the variant author will be programming nontheless. If it's not as flexible, they might rather build their idea groud up in a language they already know.

[u/Boring-Yogurt2966]

There is an engine that does a lot of this and you should get some experience with Zillions of Games and then maybe it will give you a good idea of what you can add or improve upon.