@daniel-santos why you say:
How do you know that they know and not care?
Did you try your fix? How is the router behaving from a stability and speed prospective?
There were 2 main problems with the driver of the MT7620: dropped frames that led to a very slow speed. And the fact that sometimes once it drops the frames it also get stuck forever. It seems that you are telling that you have a solution for the latter.
Do you use Openwrt 18 or LEDE as base?
LEDE unfortunately is not being updated at all. Last time that I checked I think that was already solved on OpenWrt 18. Did you look at master and the commits around September about that driver?
I wrote something about my point of view about the situation here: Xiaomi mi mini wifi: from pandorabox to lede - #11 by Camicia
If you think you can make the situation better a lot of people will be very thankful to you! 