Portable external ssd drive as a music source

Nope, your intentions are set.  Enjoy..

Let us know how that works out.

If you use it on a multi purpose computer fuhgeddadoudit Any difference you perceive is probably mental.

It all makes sense, although I'd suggest going with 2TB or even more, unless you are 1000% sure you won't be adding more music to it. Nothing worse then running out of space and having to buy yet another SSD and then moving your files to the new larger drive. From my own experience, I started with 1TB, but ran out and upgraded to 4TB, just so I wouldn't have to jump from a 2TB to a 4TB eventually.

I also personally like to leave a little headroom on the drive also, perhaps it's not necessary with music, but from being an IT guy for 20+ years,  you never wanted a disk to go past 90% full.