You have the same Custom Solution working in different tenants and you want to avoid issues with version mismatch between them.
The best practice in this case would be, when you Deploy the newest Patch Version from Test to Production, you should also Deploy this same newest Patch Version into the Test Original Solution.
By following this approach you probably won't face any issues on version mismatch when you perform the following activities:
- Merge of Change Projects;
- Copy Solution Profile;
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