Hi Simón,
Thanks for using DSSR and for posting your questions on the Forum.
You've touched a subtle, technical point. In DSSR, stacking is decided by no-zero overlapping area of (extended) base-rings projected on the mean plane of the two base normals. The two bases may be (nearly) parallel and stack well, or they are offset, and at a big angle. So being 'stacked' are not equal, as reflected by the different overlap areas and the angles. Users can filter the DSSR-derived stacks based on these two parameters.
These are just general comments. If you provide some specific examples, we can discuss in more detail.
Best regards,
Xiang-Jun