Description of feature
For handling different var spaces, this should in theory be pretty doable but can go through a number of routes:
1. Wrap in anndata.AnnData and do a concat operation
2. Wait until after denseification and apply a global index
3. Do the indexing per-anndata-chunk-array (which may have different performance than 2)
4. Yield different arrays with different spaces and leave it up to the user
Description of feature
For handling different var spaces, this should in theory be pretty doable but can go through a number of routes: