The BD series is not Convoy’s design. It’s a copy of the Dipper brand lights which aren’t made any more.
BD02 is 18650 battery and over sized head.
BD03 is S2 sized.
The reflector in the S2 and S8 are deeper (20mm x 21mm) than in the S2+ and S3 (20mm x 12mm). They have the same throw, just different sized spill light.
There is an L4 which is close to the C8 in size, but has a side switch.
There’s the X3 which takes 3 AA batteries or a 26650.
I’ve never heard of the S9. I’m not sure that is an actual Convoy brand light or someone trying to copy Simons brand. I’d be curious to know more about it.
I think all of Simons current lights are in his store, but some of his older or discontinued models are still being sold in certain large online stores, like GB and BG.