We like the 286 devices. They're simple and stable. I don't expect that you'll have any issues with them. It does take a bit of work to integrate them into provisioning since they're single line and the other devices we offer are multiple lines, but it's something we expect to do in the future. No ETA though.

Yes, for the models we support provisioning on, you'd just add them in the control panel and set the provisioning URL in the device (the specific URL for the device will be listed in control panel).

Provisioning Supported Models:

Linksys PAP2T
Linksys PAP2
Linksys RT31P2
Grandstream HT502