The Piety Briault only seems to be giving +7 Regen potency.

Tested with:

Regen 4 (base): 30/tick
Marduk's Tiara +1: 3/tick
Capped merits: 5/tick
Piety Briault: 23/tick?

After converting/casting on myself, I only received 45 HP/tick instead of the expected 61.

Thank you for looking into this matter.