Hello @krlaframboise.
Are you thinking of developing the Edge Driver to replace this DTH?
Besides the settings, do you know what functionality is missing when you use the device with the generic built-in DTH?
It’s relatively easy for ST to add custom settings for a specific device to a generic built-in driver so if the device is fully functional with a built-in handler then the manufacturer should contact ST to see if they can get their settings added to the built-in driver which will eliminate the need for a custom driver.
For the most part, the only DTHs I plan on converting into drivers are the ones for devices with unique functionality that requires custom capabilities and/or a custom presentation.
I already have it working with a driver 
I found that the “Z-Wave Switch” present in the Built in drivers, works well, because of the fingerprint added:
And yes, the only missing things are the settings, but no problem for now.
My other problem is with the Fibaro Roller Shutter 2, for my blinds. For that I cannot find any driver 
And in this case there are some settings needed, because of the button configuration, for example (momentary vs toggle). If you could help me convert my current DTH to a driver it would be great!
Converting a DTH into a driver isn’t a simple task and I don’t have that device so it’s not something I can help you with.
I won’t be converting the Dome On Off Plug DTH into an Edge Driver so it will stop working once the Groovy platform is retired, but it probably doesn’t need a custom driver.