Just D4v2, but yes, 18350 is the sweet spot for me. I’d have the black D1 in shorty mode too, if I had enough batteries.
I know everyone likes Hank’s 21700 lights cause they pack a lot more battery in about the same volume, but I’m sticking with 18650 models for the short tubes.
The D4V2 is a bit shorter and wider than the Wurkkos TS10, but they’re both perfect for EDC and they feel the same in my pocket.
Now that you mention it, the D4Sv2 is on sale right now. Maybe I’ll get one in cyan with the 26350 tube. And then try to find a battery.
I’ve never taken one apart to investigate, but I think Grandstream’s VoIP phones use something clicky like a Cherry blue switch as the hook switch (where you hang up the receiver).