Davidalumn

Surface scans are disabled for CloudDrive disks by default.  But file system scans are not (as they can be helpful)
You can disable this per disk, in the "Disk Settings" option.
As for the length, that depends on the disk.  aand no, there isn't really a way do speed this up.

I started using this week. and its $100 a year.. so there is that.
 
The professional service does a 'delete' after a successful upload.. you put 10 gig in it, it will delete 10 gig, replace it with download markers, when its succeded.
 
there does seem to be a 4,6,or 8 gig file size limit, so be sure to split the really big files.
 
 
https://www.odrive.com/account/myodrive

Yeah, this entire issue is "complicated", to say the least.
But basically, at some point, StableBit Scanner is reading the flash drive, opening a "handle" to the drive. This "handle" is what locks the drive and prevents it from being ejected. 
However, not all drives are "equal", and there are 2-3 different kinds of flash drives, IIRC. And then USB "mass storage drives".
 
 

Yup, definitely. 
And yeah, depending on the device and driver, it *may* cause odd behavior, in rare cases. 
But if this is consistently still happening, let me know. 

Seriously, their only purpose is to create stones (and then pain), from what I can tell.