According to the devs:
" Lone fighters mode
Hardcore mode without AI units will completely switch to the new custom game mechanics. You’ll also be able to gain experience in its battles, and for your convenience, there are pre-made games with classic rules that are easy to join."
Where?
The devs need to add these for every server location (at least EU and NA) and every campaign with maxed out bot counts so players will actually join instead of just avoiding it since it’s just empty maps (10v10 in LF is practically empty). If they are set up by the devs without any vote kick function you can’t use it to properly exploit XP farming anyway.
And add some hardcore squad servers as well that run constantly.