Agreed. See this test I made (time ago):From testing that I and others have done, the problem does not appear to be too many trackmarks or triggers. One tester had 350 triggers in a route without any problems with the WaitForTrigger command but adding or subtracting drivers did affect the command.
A rather medium route (120 boards or so) filled with all kind of triggers trackmarks and everything. Create a session of it. There is only one loco at this point. Wait for trigger works. Start populating the session, and (Very tedious to do) when I get to 32 locos, Wait for Trigger stops working. Great! you may say: we have the magic number. Nope, do another test with a different route, same number of locos and this time by when I get 18 locos, Wait for Trigger stops working! So what is going on here?
Now a second instance on commodities: Make a route with 2 or 3 industries and populate about 4 commodities on them. Commodity picker works, and you can see the menu showing available commodities for you to assign these to cars. But if you increase the variety of commodities (not the number, variety), at some point the picker shows nothing. Probably due to the same timeout effect due to "too many commodities". And just to be sure I am talking about commodities built-in that show no errors.
At the transition from TS12 to one of the SP's, I remember reading somewhere that for the sake of performance, timeout issues would show. But that is long ago. Hard to believe that after "The best ever" and "Best in the World" hips, things are still as they were for so long. To quantify (in my view), We have gained 30% in graphics, but 0 or very little on minute things like what we are discussing here.