I've noticed the lack of updated websites while looking for leveling kits, suspension lifts etc. Many only allow you to enter vehicle info up to 2019

I guess it will take a while for then to update but also will take time for these companies to verify their parts will work on the 2020's

example some suspension kits are offered for the 6.7 diesel or the 6.2 gas...not showing a 7.3 option.

I email all the sites asking them to update their site to include the 7.3L gasser

 

Even Ford website is very slow and clumsy, so how much you expect from aftermarket.
But good part is that 2020 body doesn't change much from previous years.
When I bought my 2017, that was 1st year of aluminium body and I went via whole lot of hassle to fit tie downs for my camper.
Coming to suspension modifications - google Sulastic hangers. I put them on my dually and now I can drive over street covers without losing a tooth.