What is the opinion of Reddit about the
WD 512GB My Passport SSD Portable Storage – USB 3.1 – Black-Gray – WDBKVX5120PSL-WESN?

Depends on the title. Some games, you can notice a significant difference (I can’t imagine playing Neverwinter without it) — other games, not so much.

Amazon has some deals right now on SSDs. This WD 512GB is normally $160 and they have it for $90.

After a bit of research I did this one:
WD 512GB My Passport SSD Portable… https://www.amazon.com/dp/B07C5BG857?ref=ppx_pop_mob_ap_share

Seems to work well under high temps as well.

I found this one is reasonably small enough.