It's a crazy-good deal - I also grabbed Gotcha Racing 2nd and the OG Guilty Gear. One thing I didn't realize is that even buying them on the JPN shop allows them to show up as purchased on my main account. Got a 1500 yen eshop card from Play-Asia and that thing has easily paid for itself with just getting all these games for $1 apiece AND getting a demo of Ghostbusters remastered to boot.
Welp, you guys finally convinced me to give it a shot. Just did the same thing myself: 1500 yen from Play-Asia. Purchased both Guilty Gears and Double Dragon IV. All 3 games show up as “Purchased” in my US eShop account, too. And because I used a Japanese account (that sits next to my US account on my Switch) instead of actually changing the region for my Switch, the funds in my US eShop balance are completely intact. Thanks for the nudge!