One of the biggest reasons I am against having a HC mode (including all those controller requiremements, special damage modes and advanced other event related options) is the way I see it LFS should always offer the most usable option as a default while offering the more advanced options as additional options. When looking at damage, it should not be whether damage is on or off. Not whether if it is reduced to some odd number or some parts of it left out. What it imho should be is options whether to carry damage to next race, for example. Same with tires. No option should not be given to disable tire heating/flat spotting. The option should be to force drivers/teams to use same tires in more than one event, or limit tire choise to one tire type etc..
Creating a HC mode with artificial limits (real time repair times, more advanced damage, more advanced control support) will only create barriers between people and make it a lot harder to move from non-HC servers to HC servers. And it would be dowbright arcade mode to have the interesting realism stuff out by choise. I would simply ditch the whole HC way of thinking and instead give the user the options for different approaches for different kind of race starting systems, tire/part choise and controller limitations/requirements etc.
LFS should offer these (I have confidence that LFS will probably offer these at some stage) different options to make the sim more realistic, not just harder or easier. For normal racing on random server, starting from the start grid with gear in neutral is a good realistic and usable basic default option but for leagues (and other seeking for more realistic experience) there should be an option to have the car in pit box the engine turned off. To start the race you need to start the engine and make your way to the starting grid (like in nk pro). And other option would be to have a warmup lap.
These options need some "sub-features". Server admin needs the commands to end/restart the race if someone stalls the car on the grid. Not restarting the whole "event" but just redo the start. Feature to change and check grid positions etc.. Or offer the possibility for these features through insim/outsim etc..