@FreeStyler Good to see you back! AFAIK, using Hitachi Microdrive driver you can do it for per drive basis. I couldn't achieve it using diskmod driver either in the past.
@FreeStyler Waiting for your feedback. Regarding the signing, please ask @Fernando 1 about ModDriverSign tool via PM.
Tried it but decided to stick with diskmod, included the diskmod driver in DaRT10 image for recovery purpose (it actually works very well!) As this is a little Server 2016 box (Intel NUC), the fact all usb drives are seen as fixed drives is't really a issue