802.11r in 18.06.1

I've just enabled 802.11r support on both my Xiaomi Mi Wifi 3G APs but still complaining about some settings.

Can you please explain me what's the best configuration for 802.11r in luci?

Should I Use FT Over DS oder Air? Which one is better?
Do i have to insert NAS-ID, MObility Domain when using WPA2-PSK? Manual says not...
Is it "good" to activate "generate PMK Locally" or does this interrupt function of the roaming?

I've also found some Tutorials to configurate R0, R1 Keys and could follow them, so just asking if this makes any difference...

Thanks a lot

There is very little useful information that I was able to find from any source on configuration of 802.11r.

After the patch in mid 2018, 802.11r should "just work" when you turn it on in OpenWrt 18.06 and later. Of course, client support of 802.11r is needed as well, which is scant except for iOS devices.

The other parameters typically don't need any changes.

Here's the original PR, at least as I understand the history. It has a discussion of the parameters any why the author chose the settings they did

on the other hand:
bridged dumb-ap's with the same ssid/key on different channels works well and needs no special sauce of any kind.

roaming will not be as fast, but usually a sub-second transition (not much worse than the delay from background channel scan).

In my experience the roaming time without 802.11r is typically in excess of 1 second. Long enough to cause FaceTime to freeze and take several seconds to recover smooth video.