I had a 14-50 outlet installed in the garage for my 2016 MX when I first got the car. I was getting ~21-22 miles/hr charge with Gen 2 cable that came with the car. Then I picked up a Gen 1 charging cable from Craigslist, and it gives me ~26-27 miles/hr.
Using the same Gen 1 cable on my new 2020 MX LR+, I am getting around ~30-31 miles/hr charge.
This is my primary charging cable at home, and it serves both MXs.
I have the Gen 2 cables in each of the MXs as my "road kit" if I can't be near an SC. But I did have to pay $35 to Tesla for a 14-50 adaptor for 2020 MX.
The only thing that is different is with my 2016 MX, when I want to stop charging, I press "stop charging" button on the main screen, and I can see the charging countown to zero, and then I can press the "unlock" button to unhook the cable from the car.
On my new 2020 MX LR+, the "stop charging" button doesn't have the same effect as the 2016 MX. It doesn't countown to zero. So I just press "unlock", and then I unhook the charging cable from the car. Although I have not tried charging with the original Gen 2 cable that came with the car or at the SC yet.