Thanks John - hope it’s been helpful. Btw I have the following TIR optics for S21D and though no picture yet, just want to touch on this topic for those buying the lights. The optics are listed in order of decreasing central/hotspot brightness, and increasing “floodiness”:
1. Sofirn Clear 10 Degree (from IF25a)
2. Convoy Clear 10 Degree
3. Convoy Beaded 10 Degree
4. Convoy Beaded 30 Degree
5. Convoy Beaded 60 Degree
Sofirn spec is not known, but I’m labeling it around 10 Degree because the beamshots are very close to the two Convoy 10 Degree optics. The two 10 Clear optics are my most favorite because I crave brightness in my Nichia lights. The Sofirn 10 Clear appears a little brighter on photographs, but measures very close to Convoy 10 Clear. I don’t see the point yet of the 10 Bead optic but pls give me some time to think about it lol .
Please note a 10 Degree optic helps with more hotspot brightness but it’s not turning S21D into a thrower by any stretch of imagination. If you want a thrower with beautiful Nichia beam color? Have to go for Convoy GT-FC40 4500K light.
If you like a more floody beam then I would go for 30 Bead. This optic has probably the best balance between flood and throw character of the 5 optics.
If you are an OCD white-wall hunter 
and want to see the most beautiful beam devoid of artifacts, if diffused and dimmer in comparison, then 60 Bead. (Though you may not notice this “beauty” advantage in real life use.) Overall, my two top choices would be either 10 Clear for throw or 30 Bead for flood. All IMHO as always.