Don't know that anyone has tried one - we haven't. Given the claim (on Amazon) that it doesn't require a driver it most likely uses the built-in modem driver (as does the Z-Stick Gen5 and the HomeSeer SmartStick+). If I had to guess, I'd say that it will probably work. Most of those interfaces use the standard Z-Wave Serial API which is what Indigo uses to talk to the interface. But we won't know for sure until someone tries one.
Not that we are aware of. The next version of Indigo (7.4.1; not yet available) includes support for the Z-WaveMe USB Stick (ZME UZB1). The changes we made for supporting the UZB1 increase the likelihood that the ZST10 will work out-of-the-box with Indigo, but we haven't yet tried it. If it doesn't work then we'll order one and troubleshoot into it.
I just got the new ZST10-700. Alas, it doesn't even show up as selectable in the Z-Wave > Configure dialog. So I guess I can report that at least the new model does not work.
I can see it in System Report as "CP2102N USB to UART Bridge Controller". And Home Assistant can connect to it just fine. But alas, no luck in Indigo.