There are two factors that affect how full the tray gets.
1: The aforementioned screw
2: Water pressure
Now from the factory they are usually set for around 70-80 PSI, RV's SHOULD be aroudn 40-55 PSI, so you may need to "Open" the setting a bit (PLUS) but I know of one RV park where the pressure is over 110 PSI, enough to blow the ends off hoses, among other things, it can blow the seals on your toilet valve (Many are rated for 60 PSI) and if that happens you need to either (First choice) use a regulator (I have both Watts and Zurin 3/4 Inch whole house regulators) or B: adjust the screw the other way.
Or C.
Remove Ice Maker, Take delight in the lack of frost build up in freezer (Greatly reduced) take advantage of added space, And get a portable "Counter Top" ice maker.