Hi

In my sub-categories descriptions, the link "Read more" is only displayed at the end of the text, not after the "Introtext word limit".
No problem in the main/root categories.

Even if I insert a link "Read more" in JCE, I just get an horizontal line in frontend, and the K2 link "Read more" is still at the end of all the text.

???

This is a template issue.
You need to locate the read more button and move it directly under the introtext.

Tested with 3 templates : same problem.

The parameter "Introtext word limit" in K2 doesn't work for categories descriptions, but only for the items in category blogs.

The category description cannot have a read more link.
Even if it did it would have to be in the template override with a simple JS check.

The category description cannot have a read more link.

On my new website, it has. But only at the end of the description text of the category. Not after the "Introtext word limit".

it would have to be in the template override with a simple JS check.

Can you explain me this "simple JS check" please ?

This possibility to have an "Introtext word limit" for the category description would be useful for me.

The simple js would be a simple toggle button.
That would hide/ show the excess height of the category's description.

I have no idea how to do that ( I often work on HTML and CSS, but I'm not a coder ).
And it seems complicate...

It 's not really. It CSS/ HTML basically.
css-tricks.com/snippets/jquery/animate-heightwidth-to-auto/

and a simpler method would be to simply swap some classes.
One with a fixed narrow height and one with height: auto.
This can be done with the addClass() / toggleClass() funtions.