Flashing different region stock from 960N (Korea) to 960F (Asia)

[BusterSG]

The specs for both models are same including CPU but 960F (Asia) support DUAL sim whereas Korea only SINGLE sim.
If I odin 960F to my Korea model phone, will it still work? or probably freeze on E.g. Settings when I click Sim 2?

How about the Samsung Pay?
If firmware 960F can work, can I use Samsung Pay in Asia? or they are some in-built mechanism E.g. Knox that will prevent this?

 

[velqn]

Same question. I have a SCV38 - Japanese KDI/AU Galaxy S9. I have only Android 9, but there are a bunch of US Snapdragon Galaxy S9 based on Android 10. Can I flash this (US firm on JP phone)? I just want to get to Android 10. I have a feeling that wont work, and I checked for the S8 - US and JP phones, altough based on QC chipset had other hardware differences...

Anyway, appreciate any advice on the matter.