Thank for your message and question.
To be honest, personally I did not yet use this UNIDUPDOCK device, so have no official information about it.
Seems interesting - and would be nice to see a developer report if possible
That could confirm if working correctly - or if there may be something to improve.
Generally I have good experiences with Startech devices and their support. Also they know and use Hard Disk Sentinel too - so it may worth to ask them directly.
They can confirm if things work correctly (or not...)
I'll try to get a such device also for testing and researching (just it may take some time....)
If somebody has any (postive or negative) experiences with it, would be nice to post here (or if I receive any details in e-mail, I'll post here too).