I am jumping into this a little late but then again I’m still new to Inovelli… I have to complement Inovelli and this community as I am really excited to read all the discussions and of course use the products. Bravo! 
I too am experiencing significant “steppy” artifacts while dimming. I have not been able to improve it much no matter what setting I adjust. I have noticed that as I raise the minimum dimmer level preference I can make the situation worse. But even with a minimum of 1% the artifacts clearly are visible — and sometimes really objectionable. I can second @MxMLssR’s report that right around the 30% value I see the worst steps. Strangely this does not change with however the minimum or maximum level preferences are set in the driver. Any value I set in Hubitat between ~28% up to ~40% will look particularly bad with things smoothing above. This does suggest that perhaps there is some driver/firmware work that can be done to improve the situation.
Furthermore I observed yesterday (and can reliably repeat) that dimming can actually reverse direction before settling. My controller is Hubitat with the latest update and I am using the Inovelli supplied drivers with the latest firmware installed on all dimmers. With any significant (approximately 10% or more) minimum dimmer level preference, dimming down from any higher value to 14% momentarily will settle darker than the desired level but then pop back up again a moment later. I can see this with incandescent and LED loads so I do not expect the quantization problem to be within the bulbs.
I can see and measure this when using any light source. LED bulbs (known to perform very well on other dimmers), incandescent bulbs (with short and long filaments), and halogen bulbs of various types including PAR bulbs in recessed downlights. I am very curious how others have improved their situations and how @EricM_Inovelli and @Eric_Inovelli can keep pushing the firmware team and/or a future hardware revision to smooth things even more. Aside from this complaint the Inovelli Red Series dimmers are second to none and perform well engineered. So I am hopeful that there are some potential improvements (with us as happy guinea pigs? 
)
Perhaps all of this is caused by some rounding errors? Or perhaps there is some sort of dither or other driver trickery that can be added to the firmware to smooth our dimming?
Thanks,
Richard
PS here’s a list of bulbs I have tested. All experience the steppy dimming artifacts. Some are poor dimming performers in general. So do not take this as a list of recommendations either good or bad but as a list of bulbs that clearly reveal this issue. At work we use the EA, Cree Pro, and Philips bulbs whenever we cannot use incandescent or halogen so I know them to be trusted dimming performers in other contexts.
- Any/All Halogen Bulbs (PAR, JDD, and Eco style A shape)
- Any/All Incandescent Bulbs (candelabra, A shape, standard filaments)
- Any/All Long Filament Incandescent Bulbs (these should have the most “smoothing” effect on any steppy dimming yet the steps are so sharp in this case that even this ole’ trick fails)
- Emery Allen EA-E26-9.5W-001-279F-D
- Emery Allen EA-E12-4.5W-001-279F-D
- Maxlite EFF8.5T12D927/JA8
- Maxlite E17A21D927/JA8
- Maxlite 103FF4B10D927
- Maxlite EF4B10D927/JA8
- Cree Pro B11-60W-P1-27K-E12-U1
- Cree Pro TA21-16027MDFH25-12DE26-1-E1
- Philips 5.5B11/PER/927-922/CL/G/E12/WGX 1FB T20 (perhaps the biggest surprise since I know these to dim to very weak levels and smoothly)