Everyone speaks how easy inconvenient it is. But nobody speaks of the downside. Banks aren't responsible for any unauthorized transfers from your phone. Someone hacks your phone takes your phone or you lose your phone it's possible to lose all your money and the bank will do nothing
You don't need to spend 3 days in a neighboring country I've done numerous border runs by absolute quickest one was 2 minutes. Laos usually takes a little bit longer but I have been out for less than an hour never an issue