There will always be disputes from people who can only see things through their own prism.
If Trials are held, then either Everyone competes or you have to go through some kind of Pre-Selection and those Pre-Selected don’t have to return for the Trials.
But who to Pre-Select? And when do you let them know they are on the team?
And how many athletes are going to thank you for dragging them home from the European circuit to compete in the Aussie winter against skinny fields in all likelihood. And while they are acclimatising from the trip home and competing in their trials, they are missing big meets in Europe.
Trials will work if: A) the Major meet is in your own Country and you have to return anyway.
B) The Major meet in at least in approximately the same Time Zone (which is why AA put on Trials - as well as “challenges” - remember Nova v that girl from Adelaide for an individual spot in the 100m? - in Darwin before the Kuala Lumpur Comm Games in 98);
C) Or if Europe stops for an extended period during which there is no comp in Europe due either to something like the Soccer World Cup (when aths meets cannot get TV, therefore cannot get sponsors, therefore cannot pay athletes, therefore suspend their activities until the way is clear).