Is there a widely used symbol for satoshi yet? Has a symbol been widely adopted for satoshi yet? I've seen Ș suggested but it's already a letter in Romanian. Ꞩ, Ȿ &amp; ẜ (long s with stroke) all seem to be otherwise unused. Has anyone suggested using any of them?
No.

Satoshi is often abbreviated to sat or s, although no currency symbol
has been widely adopted.

https://en.bitcoin.it/wiki/Satoshi_(unit)