My first post 
I bought a 1TB JetDrive SD card for my MBP M1 Pro and I formatted it as GUID APFS encrypted. All good there.
When I try to setup OneDrive to sync to my JetDrive. OneDrive would say I cannot sync to a removable media or case sensitive drive. Well that’s no good.
I have tried to use Symbolic Link but still, OneDrive has figured out is a removable media…
Any known workaround?
Welcome. I wish I had better news but AFAIK Apple no longer allows OneDrive, Dropbox, etc. to sync files to external drives.
"With the new Files On-Demand experience, the sync root is always located within users’ home directory, in a path such as:
~/Library/CloudStorage/OneDrive-Personal
As part of the upgrade, the sync root will be moved to this location. This location cannot be moved or changed and is controlled by macOS."
I have not tried this but as I’m using Mountain Duck otherwise, I think it could be a viable alternative client as its cache folder can be on an external drive, and it can sync to many cloud services incl. OneDrive.
https://blog.cyberduck.io/2023/03/07/alternative-to-the-official-dropbox-client/
Mountain Duck is interesting.
So it will mount a cloud drive as a local drive.
Do you know if Mountain Duck can sync files to a SD card?
To be honest, I haven’t tried this setup (yet) but the article linked above (Mountain Duck as an alternative to the Dropbox client) states that it will cache files on an external drive (an SD card being one of course).
Mountain Duck is really easy to use though it has many options, I suggest you download a trial and give it a go. It’s also a great tool for those cases where you do not want to sync an entire cloud to your computer but do want convenient access through a single app.
Incidentally, I also bought the JetDrive recently with similar intentions to offload some of the files there but as my MBP order is stuck somewhere with Amazon, I haven’t tried it out yet. 
BTW Mountain Duck seems to still be available on BundleHunt in their BF bundle – in case it turns out to work for you (it’s often on some sort of sale there – but it usually quickly ‘sells out’):
(Cloud Mounter is another similar tool that I haven’t tried.)
Insync will sync Onedrive files to an external folder as well.
This works, as I’ve used it in the past. However, by using the third party client, you lose out on some of the benefits of Onedrive, like editing the same file at the same time as others (not an issue if it’s just for a personal Onedrive, but was a problem for me using it for work).