In US version the default region is US.
In UN version the default region is not US. That is the only difference.

This tiny modification on US version is required by local regulations in US, which make no difference for users.

Are there any plans to implement Dynamic Frequency Selection (DFS) and Transmitter Power Control (TPC) in future firmware versions?

I don't know about their plans. But as far as I know, DFS feature only applies to channel 52~64 and 100~140, if the device doesn't open these channels, it doesn't need implement of DFS. Once they open those channels, maybe in the future, they must implement DFS.

mbambor wrote

Are there any plans to implement Dynamic Frequency Selection (DFS) and Transmitter Power Control (TPC) in future firmware versions?

Hi, I don't know about their plans. But as far as I know, DFS feature only applies to channel 52~64 and 100~140, if the device doesn't open these channels, it doesn't need implement of DFS. Once they open those channels, maybe in the future, they must implement DFS.