Btw. is inability to task-switch at all in case when there is one step more -- before pres.mode -- entering full screen is micro-variation or not. I.e. should I report it as separate issue, or wait for this one to be fixed, and see then?

> alt-tab to task-switch --> you will notice okular now is doubled.

This is actually a wanted behaviour.
The presentation mode is meant to be independent from the main window; can be moved to another virtuali desktop, or even to another screen.

(In reply to comment #1)
> Btw. is inability to task-switch at all in case when there is one step more --
> before pres.mode -- entering full screen is micro-variation or not.

Uh?

> This is actually a wanted behaviour.
> The presentation mode is meant to be independent from the main
> window; can be moved to another virtuali desktop, or even to
> another screen.

Oh, I see, this is useful then. So let's make it a wish -- please provide option for it. Current behaviour is useful but single window is useful when okular serves as reader (and presentation mode is perfect for it -- black background, page takes entire screen), but doubling entries in the list is obstacle when task-switching.

> > Btw. is inability to task-switch at all in case when there is one
> > step more -- before pres.mode -- entering full screen is
> > micro-variation or not.
>
> Uh?

I see it is a separate issue:
https://bugs.kde.org/show_bug.cgi?id=186819

(In reply to comment #3)
> > This is actually a wanted behaviour.
> > The presentation mode is meant to be independent from the main
> > window; can be moved to another virtuali desktop, or even to
> > another screen.
> 
> Oh, I see, this is useful then. So let's make it a wish -- please provide
> option for it.

Oh please, don't start it like that.

Ok, I rephrase:

* please provide new presentation mode which would open in the same window as current, in other words it would run in single window (as opposite to doubled window, as now)

So, introducing option avoided.

Just in case -- the reason is for this wish is, I read not only one doc, but several and switch between them. So having 10 docs leads currently to 20 windows, I have to make all hoops to keep sane track of those windows.

Presentation mode is not meant primary "for reading", but for "presenting" the document to others (fullscreen is meant for that).
Anyway, your use case is much border line, and thus it won't be implemented.

You mean it is prohibited for users to read in presentation mode? Besides how it is helpful to have two windows at presentation instead of one in the same desktop? What benefit of it?

Presentation and fullscreen are not similar -- in presentation mode the entire space if for page, it works in per page mode thus it is more suitable for reading. Fullscreen is ok for just look here and there.