Afaik, (not tested by myself but seen on Github and forum responses).
There is no luci app for mtk, but instead the normal wireless menu item which you should expect.
Unto further reading, some reported to have no phy for 6ghz, but they confirmed that it only becomes visible if the country settings are correct, some countries don't support the full 6ghz band, I'm not sure if that is something you also are seeing in the mtk sdk, this however are completely different implementations with OpenWrt as base.
As for MLO, this is just my personal untested opinion, I think the drivers are not fully mature for it to work stable I just compare it with the history of older wifi standards here, it takes close to a new wifi standard to say all quircks and issues are gone, minimum a year or two, from now I think they already at a year or close to it, luckily the banana pi had this chip quite some time allowing developers to support things alot earlier.
So it will not be strange to experience some issues or corner cases on this field 
Edit:
I didn't read properly, i didn't notice bridge issues myself with vanilla.