I wish discord would support fast account user switching. I vastly prefer it to slack but I also enjoy having good workplace hygiene so having my gaming friends pop up during my work hours is less than ideal.
Not supporting multiple identities is discords biggest feature gap IMO. On windows you can use sandboxie to start multiple instances in parallel using different credentials, but it's somewhat annoying to use and breaks occasionally.
You should try running your Discords in Firefox Containers [1]. Even if you don’t use Firefox to browse, it’s superior to Sandboxie for containing multiple Discord instances.
[1]: https://addons.mozilla.org/en-US/firefox/addon/multi-account...