Apologies if I have totally confused this thread in my own confusion. My brain does not work at its best in my current state of health. I haven’t even managed to say hello properly yet which should have been my first post! (I will try to do that soon).
I couldn’t understand why one would want to go left or right until I realised after more playing with it now that it must be because you have the “View items as icons” option checked in the Application Finder preferences. So you have a grid of options within which you can navigate to the left and right. (I always change settings to my own preferences so quickly that I forget how things are set by default).
Assuming this is correct, then perhaps @kinu could try how they find the experience after unchecking the “View items as icons” option. This gives you a simple vertical list of results which can be navigated immediately with the up and down arrows without any delay.