Thanks for the review!

Here is what's making the trouble:
The Firefox has no API which would allow an addon to get a list of all the active elements on the page. Tho get around this, KS requests a list of all links and then scans them all one by one to determine which ones are visible. The unanticipated problem was and is that this scanning process is very slow. Therefore, KS needs time to determine which elements are active. Furthermore, it does not actually scan all elements, it skips some things in order to increase the scanning speed.

So, KS will sometimes not be able to detect all links. Also, if a webpage is big and full of links, KS will need time to scan (and re-scan) them all.

I think I have figured out a way to get around this issue, but it is a big job as I will have to tear apart the entire code for finding links. There are many other issues I found in KS, so this all has to be fixed together, and it will require a month of my time. Unfortunately, I won't have a free month for another year or so.

Therefore, all improvements for KS are currently on hold.

I really like this addon, I am using it all the time, but it is not very high on my list of priorities, primarily due to a total lack of active users.

As for the "Pause" key, I would suggest that you find some hotkey utility for Mac which can emulate the "Pause" key, because on some pages KS will mess up and you will need a way to disable it.

When I was choosing a hotkey, I was looking at common keys included on PC laptops. Mac didn't cross my mind.