This would explain the different but similar round die I found in SFT-25R and W5050SQ3.
So according to your information Luminus seems to be the emitter manufacturing department of Sanan. (Luminus belongs 100 % to Sanan)
What surprises me is that LatticePower seems to list a wide variety of emitters on its own website. If they don’t manufacture them themselves (only the chips), who makes the LEDs for LatticePower?
O I get it right, ChangDa manufactures other LEDs like SFH73, SFN55.2 and so on? Can you confirm that the Luminus LEDs like SFT-40 or SST-25 are actually made by Luminus themselves or are they made by ChangDa and just relabeled for Luminus?
Do you have any sources to back up this information? Then I can adapt my tests and change them slightly if necessary.