I think this deservers own topic. As I did read now that clutch wear will be implemented, old slush box type of gerabox becomes quite critical for various type of vehicles, lower level drag racing for example, but also some street cars never came with manual boxes. One can probably still set clutch heat and wear to zero, but real deal would be nice. Ability to set stall speed, torque converter factor and how sharp shifts are low / high throttle, also if top gear(s) have locking ability, these are things that should be possible to adjust. For engine side, it would be possible to achieve all of this by adjusting clutch appropriately, if one likes to go easy route, then some gear changing adjustments according to load throttle position would be needed, like kick down etc. Surely replacing clutch with properly simulated automatic box would be great, but not really necessarily, most important would be having slip and poor engine braking, changing shift points based on throttle would be a bonus already. It is whole different than automatic gears currently implemented, driving is different as is acceleration, grip etc. From there it would be then easy to implement manually shifted automatic used in some drag racing cars and other variants too.
I though that code for this would also benefit newer cars as many has still conventional automatic, some has manual shifting modes with it though. Then also CVT type transmission would be possible with clever settings, I believe. In US most cars on street are probably automatics and such is used in drag racing and I believe some local dirt ovals too they race with cheap vehicles that have stock transmission etc?