I paired around half-a-dozen Dimmer 2s with my C7 around a year ago when I migrated from Smartthings; the Dimmers themselves were purchased over a several year period before then, and have never had a firmware update.
A little fiddly to get into pairing mode in the first place, but TBH I've always found that to be the case with Fibaro devices, on Smartthings as well as Hubitat. Once paired everything worked smoothly, with the only bump being the "swap S1 and S2" setting I wanted to apply on one Dimmer but couldn't find a driver to support. Rather than start any fiddly driver code editing I finished up temporarily switching to the basic Z-Wave tool, editing the appropriate parameter's value, then switching back to a "proper" driver and that sorted things.
