[parkher]

In the meantime, I was playing a bit more with my toy and Alita.
Perhaps somebody is thinking about getting this toy, so here is what I found out so far.

There is nothing left to play with the default reader app, but I was experimenting with Cool Reader. So I was able to use both left and right mouse buttons (the red protruding buttons) as next page / previous page buttons. They are very conveniently placed to be used for this purpose. Also a tap on the touch pad turns pages then. But the mouse pointer shows up and stays on the screen for approximately 3 seconds after the page is turned. No big deal, because it shows up in the middle of the screen (or wherever you left it), and does not affect reading at the top of the page. And then it is gone. Interesting - I was able to reconfigure the right mouse button as a key action, but the left mouse button - as a tap zone action of the central tap zone. And it has consequences - read on!
In addition to that, I was able to use some more buttons on the toy for anything I wanted, including for next page: Escape, Menu (I think it is Menu), Back, 8 (F9/*) buttons. But not Home button. OK button and Enter only make the mouse cursor to appear. As posted earlier, all four arrows keys are working in CR and volume-/volume+ keys are working as well. Volume Mute key actually mutes the sound.
Also, double click and long press are working and can be configured for different actions, so 3 times more working buttons on the toy (if you use it not for actions but as a keyboard to enter text - then all the keys are working, not sure about some multimedia keys, though). Long press - you can hold the key pressed until the action occurs, then release it. But you must be careful with double click, if the pause between clicks is too big, you will get a single click twice. So, for example, you may have next page and previous page on the same button. Click once - next page, click twice - previous page. Or click and hold until you visually see the page turned back - previous page. Etc.
However, funny thing - the left mouse button - which is reconfigured not as a key action but as a tap zone action. So, because of that it has only two key actions (for the tap zone), not three. The third one is global.
I have the secondary action configured as double tap, and for selecting words / going to the dictionary I use the long tap.
So, the left mouse button works on a single click, on a double click, and - as should be expected - the long press causes a word to be selected and GoldenDict opened.
In principle you can press OK, get the cursor on the screen, move it to a word with touch pad and then press and hold the left mouse button to get it translated.
But moving the cursor with precision to a desired word on an e-ink screen is pretty tricky. Also, you should not accidentally make a tap on the touch screen (an action! - unless you define it as no action) while dragging the cursor.
But it works. If you really want to use the dictionary without swaying your Alita in the gooseneck holder.