Is processing geometry changes in DSM taking too long?

This is most likely due to a large facet count and a high rendering quality setting.

In your design structure tree, try creating new components and moving some solids/surfaces into these sub-groups.

You can also export your current design as a new RSDOC file (use a different name) and resume work on this file. This can also fix file bloat issues (for complex designs) and make DSM faster to work with.