Question Flash Korean snapdragon firmware to G998U1 to change available 5G bands

[Josef12321]

Hello,
can I flash the Korean snapdragon firmware to an American model (G998U1)?
If yes, will this change the available 5G bands to the ones in Korea? Thanks.

 

[Dolgogi]

Korean model is Exynos this year.
Also, from reading the specs on Samsung Korea's Web site, it only supports N78 & N77 Sub6 bands

https://www.samsung.com/sec/smartphones/galaxy-s21-ultra-5g/specs/

 

[dark11b]

Yesterday I tried flashing my U1 with a Taiwanese firmware and it did not succeed. I'm having the same issues with bands. Where I am they are using bands B3 + B20 for carrier aggregation. So right now I am only able to get LTE and not LTE-Advanced. I guess I'm missing some sort of profile? Because the phone does support these bands.