I wrote something similar a few years ago and I didn't know this thread even existed until just now. It's written better than my attempt too:
https://www.ffxiah.com/forum/topic/53815/offsite-backups-for-your-ffxi-customizations/
All in all, I support and and all backup strategies as a matter of principle.
I could parameterize the script too if anyone finds this to be too technical.
Edit: I'm now reminded why I wrote this in the first place. I couldn't get Dropbox in 2019 to follow symbolic links to my Windower/Ashita folders. Does this work today in 2022? (If anyone is curious, mklink /D will create a "Windows Junction" or hardlink). This means the Dropbox folder and Gearswap/Data folder point to the same physical blocks on the hard drive. Your updates automatically sync via Dropbox as you make edits and press Save.
I'm genuinely curious if anyone runs into trouble using symlinks as described in the OP.