I was looking into this same issue today, i have a gs43vr 6re. And the only thing that I've been worried about is that it seems all the people doing this are using samsung drives for both drives.
I found the best answer here. but it still requires both drives to be samsung.
I was hoping to partition my 1TB HDD(non samsung) and clone the 128GB nvme to this new partition.
Then I wanted to reboot using the partition after swapping out the smaller nvme and replacing it with a 512GB nvme.
Then clone back to the new nvme and should fire up,
Now Im inclined to use a Samsung 500gb SSD I bought a while back and never used as an external drive to clone the nvme to.
Then boot from it after installing the new nvme.
Then clone again.
Remove the external and boot using the new nvme.
Id appreciate any thoughts or advice on these competing paths.