You can change the default branch on your github repo to something other than 1.1.x, which will probably lead to less confusion. But I thought, why not take it further? So I pushed a CHOOSE_VERSION branch:
Just make sure that’s all accurate, and change it to the default branch in your settings, and people will be greeted with that readme file instead of the Marlin readme file. As a bonus, if they blindly clone, they will get instructions instead of headaches.
But, imho, too much declarations at begin that user have to refer or remember when making choice.
it’s better to divide to chapters by machine. With h1 header. Then explain each machine with list of firmware. For mpcnc/lr also you may make subchapters by board type.