I just installed a 10 degree TIR from LEDDNA in my S2+.
The original OP reflector was not great for throw. With an XPL HI V2 3D emitter at around 5A, the throw was 13,500cd with original OP reflector. With the TIR properly adjusted so the emitter image filled the reflector, the throw increased to 21,500cd at around 5A.
I’m very happy with the improvement. It seemed to reduce spill, and also reduced the corona around the hotspot some. So the hotspot is a bit more well defined, but there is still a nice gradient from the hotspot to the spill. The TIR throws about as well as the smooth S2 reflector. With the same emitter with the smooth S2 reflector, the throw was 23,000cd.
It took a little fiddling to get the TIR installed correctly. The white holder it came in was too large to fit in the S2+ head. Also, the bottom of the white holder is flat, so the solder joints on the MCPCB prevent the TIR from sitting correctly. So I had to remove the white holder. The correct focus was achieved when the bottom of the TIR was about even with the surface of the XPL HI, so an appropriate spacer is needed. I cut out the part of the white plastic holder that fit around the emitter and used this as a spacer. The TIR without the white holder almost fit nicely in the bezel of the S2+ head, but with the oring in place the TIR would not sit quite completely level, so I kept the glass lens in place to keep everything level and maintain water resistance.