Currently my 2 bay has 2 14TB's running in Raid1. I have a 10TB as an external drive, and also ordered a 14tb (that will come several days before the 4 bay) and want to prepare the switch to SHR for the 4 bay but keep all the data. I remember reading that if I use different drive sizes I want to start off with the lower capacity drives first?

Would this be the correct process (I'm aware of the risk but don't have the money to get another drive, the drives are still slightly under 2 years old):

1) Power down and take out drive #2 14TB (that's running in raid 1)

2) Put that drive #2 in an usb enclosure and format it as ntsf while connected to my pc to transfer the 10tb external to it

3) Put in the 10TB drive and the new (drive #4) 14tb into my 2 bay nas and format them into SHR

4) Connect the 14tb external to the NAS USB to copy all the files to the SHR pool

5) Power down and wait to receive the 4 bay and then only put in the 1st 14TB drive to run the migration thing

6) Power down, remove external drive from enclosure and add all drives to the 4 bay

7) Turn on and add drive #2 to the SHR pool

8) Copy all drive #1 data to SHR pool

9) Add drive #1 to SHR pool. finished?

Would the above process work, or am I better off waiting until the 4 bay and doing similar process in (after I do the migration) that I wipe drive #2 (and make it basic) to copy the 10tb external to it, and then add it to the 4 bay and then continuing from step 3 with minor changes?

Thank you in advance!