Is there a way to cycle through multiple solutions to an assembly mate, before finalizing the mate command?
What type of mate? For coincident mates there is a button to flip the orientation back and forth before finalizing the mate.
After you select first entity, only valid mates remains available to check (for example, start Mate cmd > select a Vertex ... Parallel mate is gray out, since is not a valid mate for Vertex entity). In this way, you can select both entities and then you can switch to other mate type if that is available. To see all combinations for each entity, please see help file for example.
If you are interested in a specific workflow, I think you need to elaborate a little bit more your question.
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