[monksy]

Is it possible to put an addon, i.e. youtube or curiousity stream, as a main menu item on the theme? It does not look like it's a category that is possible in the settings.

[pkscout]

Not with the stock Estuary, no.  Some skins do allow this, and there was an Estuary mod for Leia that would do that, but I'm not sure that mod every got updated for Matrix.

[the_other_guy]

Is it possible to put an addon, i.e. youtube or curiousity stream, as a main menu item on the theme? It does not look like it's a category that is possible in the settings.

you need to edit theme
1 add to favourites
open \AppData\Roaming\Kodi\userdata\favourites.xml
copy link  ActivateWindow(10025,"plugin://plugin.video.youtube",return)
open home.xml
find
    <control type="fixedlist" id="9000">

xm:


    <item>

                            <label>$LOCALIZE[20389]</label>

                            <property name="menu_id">$NUMBER[16000]</property>

                            <onclick>ActivateWindow(Videos,musicvideos,return)</onclick>

                            <thumb>icons/sidemenu/musicvideos.png</thumb>

                            <property name="id">musicvideos</property>

                            <visible>!Skin.HasSetting(HomeMenuNoMusicVideoButton)</visible>

                        </item>

 <label>youtube</label>
 <property name="menu_id">$NUMBER[16000]</property> $NUMBER[5000] movies $NUMBER[6000] tv shows
<onclick>ActivateWindow(10025,&quot;plugin://plugin.video.youtube&quot;,return)</onclick>
                       <thumb>icons/sidemenu/musicvideos.png</thumb>     <favourite name="YouTube" thumb=" ?? \addons\plugin.video.youtube\icon.png"
       <property name="id">musicvideos</property> if $NUMBER[5000] movies  $NUMBER[6000] tv shows  or blank if you just need menu
                            <visible>!Skin.HasSetting(HomeMenuNoMusicVideoButton)</visible>

xm:


    <item>

                            <label>youtube</label>

                            <property name="menu_id"></property>

                          <onclick>ActivateWindow(10025,&quot;plugin://plugin.video.youtube&quot;,return)</onclick>

                            <thumb></thumb>

                            <property name="id"></property>

                            <visible></visible>

                        </item>