It speaks

here I think.

Dev Blog: Crafting in Darktide - Warhammer 40,000: Darktide / Announcements - Fatshark Forums (fatsharkgames.com)

Earn Blessing

You may also choose to surrender a weapon to Hadron in exchange for a Votive Offering dedicated to one of the weapon’s Blessings. This allows you to extract the Blessings you are interested in from weapons you no longer want, and collect them for use with the Combine or Re-Bless actions.

Combine Blessings

At the Shrine you may choose to combine three Votive Offerings into a single upgraded Votive Offering. Currently, most Votive Offerings have a maximum Tier of IV, but there are some exceptions to this. We’re testing a few different options with the requirements and the results of combining these Votive Offerings.

Re-Bless

By Re-Blessing a weapon in the Shrine, you can replace a weapon’s existing Blessing by expending a Votive Offering from your collection, further tailoring the weapon to your liking. The weapon gains the Blessing associated with the chosen Votive Offering -he original Blessing is lost in the process.

But probably subject to change who knows.