For confirmation I decided to put up a Tatara in Highsec on SISI to test out the Reprocessing Yields, and here are my finding:
Refinery Reprocessing Formula:
BY = Base Yield
RM = Rig Modifier || Tech1 is 1 == 1% and Tech2 is 3 == 3%.
StM = Structure Modifier || Athanor is 0.02 == 2%, Tatara is 0.04 == 4%.
SeM = Security Modifier || Lowsec is 0.06 == 6%, Null/WH space is 0.12 == 12%
R = Reprocessing Skill level
RE = Reprocessing Efficiency level
OP = Specific Ore Processing Skill level
IM = Implant, which comes in 1%, 2% and 4% or 0.01, 0.02 and 0.04 respectively
NOTE: Security Modifier only apply if Rig is installed
I hope this makes sense to my fellow capsuleers, just for good measure I will give a few screenshots as documentation (Left: HS Tatara with no Rig, Right: HS Tatara with T2 Rig):