I think it would be helpful if the higher grade dark matter could be used to repair lower level equipment. For example a grade 5 dark matter could be used to repair gear from level 1 to 50, and a grade 3 dark matter could be used to repair gear level 1 to 30.

This would be very nice for any high level gatherer who would prefer to only take up one inventory space instead of as many as 5, or anyone who happened to run out of a lower grade dark matter out in the field but just so happens to have some higher grade dark matter with them.