ContentEntityStorageTrait can't be used outside Multiversion

Currently working on a project with a few custom entities that needs to be deployable in addition to nodes ; those entities have a custom storage backend, and use ContentEntityStorageTrait; to get the various Multiversion helpers.

It almost work, except that buildQuery returns early and doesn't correctly handle deleted entties.

Right now, there's

    // Prevent to modify the query before entity type updates.
    if (strpos($this->entityType->getStorageClass(), 'Drupal\multiversion\Entity\Storage') === FALSE) {
      return $query;
    }

In ContentEntityStorageTrait, which prevents using the trait with any storage class that's not explicitely in the Multiversion namespace. It'd be very nice to improve that.

I think the easiest fix to get in would be to simply change that to check that the storage implements Multiversion ContentEntityStorageInterface.