I'll mainly be using the iMac for Photoshop and Logic Pro X applications. Would the Samsung T7 be fast enough for those applications to directly use it? That is, both Photoshop and Logic Pro X to work on projects that are directly on the Samsung T7 without having to transfer files between it and the iMac?
I don't use Logic Pro, and for Photoshop I usually work directly on files in my 2TB internal SSD.
However I did just try some photoshop adjustments of a large (180MP) photo file on the T7, and it seemed fine.
Afaik PS loads the workspace into RAM, so plenty of RAM would be important (I have 32GB, which I recommend as minimum, you can get 2x16GB sticks for ~$120).
Of course, have the PS app on the internal SSD, and only the project files on the external SSD. Keep the PS "scratch disks" on the internal SSD, which is the default.
However, it would be best if you hear from someone who regularly works from an external SSD like the T7. I don't want to say it seems fine, then you try it and are disappointed