[parkher]

Yes, pretty simple.

I have it mapped on long OK, so 1 press instead of 2 to get to it.

So, after pressing and holding OK, the dictionary shows up.

Then you have to select the word you want to look up. You do this with arrows.
Initially you have to navigate from the 1st word on the top line, and the dictionary shows up at the bottom.
If the word you need is in the bottom half of the page, you can press UP and get from the top line to the bottom line at once, the dictionary then moves to the top.
So you only need to navigate up-down no more than through half of the page.

Similarly, you only need to navigate through half of the line, however, by moving beyond the line you do not get to the other end of the same line, you get to the next/previous line, so you have to keep this in mind when navigating, in order to minimize the number of required arrow presses, otherwise you may overshoot.

If you need to use the dictionary again on the same page, the last chosen word is remembered and the top/bottom location of the dictionary as well.
So then you have to navigate starting from that word, not from the top of the page.

Also, there are some things you can do on the dictionary menu bar (to which you can get by pressing short OK): to choose the single word or the compact multi-word mode, to switch to another dictionary, to fetch the virtual keyboard.

However, if you want to look up a word that was not on the page, but was used in the dictionary itself to describe another word, or in an example, you cannot select it, you have to type it in with the virtual keyboard, unfortunately. Or to scroll to it in the multi-word mode, which is in most cases even worse than typing it in.
They could add another button to the menu bar to allow choosing a word inside the visible dictionary page.