We will release 6.2 on Tuesday, after making sure there are no last minute issues.

Thanks for reporting this to Apple. it is a long outstanding bug.

It has been almost two weeks since I... 

• System Preferences > Energy Saver > Power > Prevent your Mac from sleeping automatically when the display sleeps — ON
• System Preferences > Energy Saver > Power > Put hard disks to sleep when possible — OFF
• System Preferences > Energy Saver > Schedule > Sleep — OFF

…and the RAID array has not disconnected once. Prior to that it was disconnecting once or twice a day, so I am satisfied that the work-around is a success, but it should not be necessary to use a work-around. One other item, until I changed those settings other external drives were also disconnecting as well so the issue would appear to be Apple's and has been reported via Feedback Assistant. 

I have not encountered the disconnect of either the RAID array or the USB drive since I changing all the Energy Saver settings, but it is still early days. So rather than confuse the solution space I will let that ride for a few days before changing anything else. If it does recur I will let you know and take your advice and reorder the chain and see if that has any effect. Thanks

I have not been able to reproduce this, as I suspected. this is mostly a hardware issue where a Thunderbolt chip somewhere is resetting.

try moving cables around, resetting them. reorder your other enclosure to put it "first" and see if the ejects only happen further down the chain (your main enclosure, as if the main enclosure is resetting the bus,  then it won't affect devices before it in the chain, is my theory.)

• System Preferences > Energy Saver > Power > Prevent your Mac from sleeping automatically when the display sleeps — ON
• System Preferences > Energy Saver > Power > Put hard disks to sleep when possible — OFF
• System Preferences > Energy Saver > Schedule > Sleep — OFF

NOTE: another HD not associated with the RAID array has also reported several unexpected dismounts as well.

Thanks. SoftRAID 6.1 will be adding full APFS support, at present the application does not understand APFS.

I understand the driver issue, that you must "Allow". This is something that is being looked at, yes.

1. When I installed the new driver. SoftRAID reported "your system is now ready to be used". Had I not known from previous experience to open System Preferences > Security & Privacy and approve OWC it would not be running.
2. SoftRAID 6.1 b 2 reports the format of the array as unknown (it is APFS) so I assume the APFS compatibility is yet to be worked out. That is disappointing.
3. Other than those two outstanding issues I am well pleased and want to say to one and all, well done.

Good to know. So far it's been working perfectly for me.

I don't think I formatted it APFS. Waiting for the go-ahead from you guys. Probably won't do it until I have Monterey. 

Just downloaded beta 2. Backup time!