Clarity on --drive-server-side-across-configs

here is the main post in that topic
https://forum.rclone.org/t/transfer-2tb-of-data-from-a-google-drive-edu-account-into-google-one/33994/23?u=asdffdsa

fwiw, i am bit paranoid, would not use rclone move, but do a two-step
rclone copy from source to dest
rclone delete/purge the source or use the gdrive web interface