Hey@m-mohr, thanks for making a start on this. I wanted to check, doeshttps://github.com/geopandas/geopandas/pull/3597/files also cover this use case?
I suppse you have to know about attrs, and know geopandas preserves it, but it also gives a way of writing arbitrary metadata - and also a way to retrieve it.

There's potentially still value in having this too, but interested in your thoughts.

Neither of these solutions deal with the schema updating you listed in your original issue though, that would probably need a mechanism like this.

Thanks for the pointer. Indeed, I want to update this to actually cover updating the schema. This was a first attempt just to get going and realized during the night that I actually need more than just metadata ;-)

I've updated the PR accordingly, see the updated PR description above for more details.
Setting this as ready for review to get some first reviews of whether the concept would be acceptable.
Happy to finetune as requested and potentially fix the codecov issue then as well (although not exactly sure what to do yet), but first want to get first opinions before spending more time on it.

#3597 is not solving the issue because it adds metadata to PANDA_ATTRS, but I would neet it separately, i.e. not inside of PANDA_ATTRS.