Just to weigh in on the setup issue quickly, I do see people's points about liking modifying setups for drivability, but in my experience, with a few exceptions, a *good* fixed setup closes the field up, rather than spreading it out. If there are weaknesses in a setup everyone has to deal with that equally. As far as slower drivers being able to compensate for their pace with a setup, I don't think I've ever seen that. Sure, if a car as a *bad* default setup, changing things can be important, but where the default is drivable, or the fixed setup is a decent custom one, less experienced drivers are not going to have any issues whatsoever.
Needing custom setups to be able to compete simply isn't true. If everyone else has a custom setup for a car which has an extremly bad default one and you don't, then sure, it's important, but at the end of the day I doubt we're ever going to drive a car with a fixed setup that's undrivable. If everyone is on a level playingfield with how the car drives, providing those characteristics aren't too extreme, it's by definition much fairer.
As someone often towards the front (but not as often as I'd like), I don't at all feel like I'm being put at a disadvantage by not being able to change things, again, providing the fixed setup is sensible. Through practice in the F3s I can often gain multiple seconds of lap time when I'm creating the setup, but firstly, the lap time doesn't come from the setup, and secondly, if there are gains to be made and nobody can make them then it doesn't matter!
My setups for the F3s are not significantly faster than default (depending on type of circuit and aero requirements ofc) for most drivers, I just find them more comfortable for my driving style when I'm pushing hard, and I share them for that exact reason. If it makes the car easier for some of the less experienced guys then mission acomplished, but it's not making anyone all that much faster. Taking that away would simply mean we'd all have the same limitations of that car. For example, the F3 on default setup I find can be quite understeer-y on entry to high speed corners. If we all had that limitation then our high-speed entry speeds would all simply be slower, we'd all have to adapt, and nobody would gain or lose.
There are always going to be drivers who struggle less with car control than others, but butchering a setup in order to suit a driving style that is causing a lot of mistakes or difficulties with a car is really counter-productive to improving over time. Setting the rear ARB to a super low setting because you spin a lot in a specific corner might make that spin less likely, but it's going to counteract any gains made through confidence with losses in laptime potential of the car. Again, assuming we are comparing to a drivable fixed setup, it's always better to learn to adapt to the car than the other way around. *Then* you might start editing setups to improve.
This is not me trying to tell you that you can't achieve faster laptimes through setup work as clearly that is false. It is more than it's the process of drive, analyse, adjust, improve that gives you those gains, and there's no reason why that can't be done on a fixed setup. You are removing a tool, but a tool for everyone. When I've done coaching and engineering for other drivers, the coaching part has always been a far bigger impact on their speed and consistency than the engineering. I would only ever suggest any setup changes after their approach is consistent anyway, so, beyond those major base track adaptations like wing levels and gear ratios, the setup isn't really where the laptime is gained until you're up in that 95th percentile. And when you're up there, it's more the setup allowing you to do something easier, rather than the setup actually giving you that pace. This isn't F1 where tiny suspension changes masssively affect aero efficiency and *actually* gain you grip - in sim things simply aren't that precise, so unless we're in exploit terratory like running max camber and silly things like that, you're not gaining grip, simply changing balance - something which we should be doing with our feet, not with MoTeC.
Rant over.
If it were me, I'd fix the setups to a custom one, but that is an enormous amount of work to put in. If the fixed setup is easy to drive, it also probably wouldn't really gain us much, especially as there aren't that many options to adjust with the F4. Fixed for this is perfect, in my opinion.