By "4KB enclosure" I mean any dock or enclosure which incorporates a USB-SATA bridge whose firmware is configured to report a 4KB sector size to the USB host. The host PC sees a 4Kn USB mass storage device, even though the actual HDD behind the bridge is a 512e device. When the host OS writes a 4KB sector to the bridge, the bridge firmware splits it into eight 512-byte logical sectors (LBAs), and these 8 sectors are then written to the 512e drive. All this happens transparently to the OS.
The reason for this approach is in order to circumvent the 2TiB capacity limit of MBR partitions. Each partition record in the partition table in sector 0 has 4 bytes allocated to the partition size. These 4 bytes represent the number of sectors in the partition. The largest number than can be stored in 4 bytes is 2^32, ie approximately 4 billion. So this means that the maximum capacity of an MBR partition is 4 billion sectors, which for 512e sectors amounts to 2TiB (= 512 x 2^32 bytes). One way to increase the capacity limit beyond 2TiB is to increase the sector size. Seagate chose 4KB which then means that the new limit becomes 16TiB.
So now when the OS examines the partition records in sector 0, it sees the total number of sectors, not the actual capacity in bytes. The total capacity now depends on the sector size which is reported to the host by the drive (internal) or the bridge (external).
The "8TB firmware upgrade" for the Sabrent is ambiguous. Early enclosures were limited to 32-bit LBAs, which meant that any drive larger than 2TiB would be truncated. For example, a 3TB drive has 5,860,533,168 sectors.
In hexadecimal notation this is …
This number consists of 33 bits. If the bridge firmware has a 32-bit LBA limitation, then it will see only 0x5D50A3B0 sectors, ie the leading "1" will be ignored.
The reported capacity will then be ...
- 0x5D50A3B0 sectors x 512 bytes per sector = 801GB or 746GiB
The ATA standard supports 48-bit LBAs, as do all modern drives. It could be that the Sabrent upgrade involves the addition of 48-bit LBA support. However, this means that capacities would not be limited to 8TB, as the marketing statement would imply.
As for your question regarding DMDE screenshots, it does not matter which OS DMDE runs under -- the output will be the same.