I have put 40 start position objects in the layout. Should I put also 40 pit start points? If there are less start points, does it mean that not all 40 can join track even they would join different time?
If you place 40 start positions and 39 pit start points,the 40th car will be spawn on 40th grid position when joining. I'd say that's a yes to your 1st question.
Okay. If I understood correct, when expanding a grid of an original track, I need to add only the missing pit start points. Looks like FE6 has 18 start points by default, so I am missing 22 start points...
Obviously it is also important to give correct numbers to those additional pit start points...
A tip that I discovered later, you can test your custrom pit with AI by copying the pit objects from X/Y layout to the closed config lyt file, for example fe6.lyt or fe6r.lyt