And lastly, a GPT disk is meant to be booted in UEFI mode and can't be booted in Legacy BIOS mode, while an MBR disk is exactly the opposite.

The Recovery partition is also tagged in a particular way, but that mechanism is different on GPT disks vs. The EFI partition (small FAT32) and MSR (the weird one you mentioned) are both meant for GPT disks set up for UEFI booting and wouldn't be applicable to an MBR disk. Second, since you apparently hope to be able to boot from that disk, you'll have the additional issue that the partition layout required to boot from a GPT disk is completely different from what's required to boot from an MBR disk. First, you're going to face the issue that MBR disks can only have 4 total primary partitions.

If the disk has to remain MBR and keep those existing partitions, then cloning isn't going to work here for a few different reasons. Does the HDD have to remain MBR? And what's on those existing 250 GB partitions? If you can dump those partitions, then tell Reflect to clone the entire SSD to the HDD and it will switch it to GPT.

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