I am not 100% sure about the adjusting set up on the ZS EV but I am willing to bet that you are absolutely bang on with your theory
@Alb .
Normally you will find, if you choose a suitable size sewing ? needle, that is a good fit in the centre hole of the jet, you will be able to use the leverage of the needle to move the position of the actual ball type jet.
Basically the washer jet is a simple metal sphere, with hole passing through it.
It is mounted inside of the plastic housing but can be adjusted.
Only a very small movement in the ball jet, will alter the direction of spray jet a lot.
It’s a lot easier if you get someone to press the screen washers while YOU make the small adjustments to each jet, or you could be there a while ?.
This simple but effective system has been used for many many years now.