Dredging up this old topic. I installed Enpass 6.6.3 (840) from the Mac App Store today. Imported from 1Password7 and all of my items in Enpass show the import time and date as both the Created and Modified dates. I looked in the .1pif data and all of the dates in there are correct (not reset to today).
I am trialing Enpass as a possible paid family user to replace 1Password when it goes to version 8. While Enpass doesn't have all of the features, it has enough for me to move. Except I won't move if I lose all of the created and modified times.