Possible typos

[tbm]

unstable/wlr-output-management-unstable-v1.xml

      <arg name="refresh" type="int" summary="vertical refresh rate in mHz"/>
...
      <arg name="refresh" type="int" summary="vertical refresh rate in mHz or zero"/>

s/mHz/MHz/ ?

unstable/wlr-output-power-management-unstable-v1.xml

      <entry name="invalid_mode" value="1" summary="inexistent power save mode"/>

s/inexistent/nonexistent/ ?

[hd1ex]

s/mHz/MHz/ ?

Actually this means milli-hertz.
They did this to fit a fractional frequency into an integer value.
So there should be no typo here (see the description in the core wayland protocol).

s/inexistent/nonexistent/ ?

I'm no native English speaker but it seems like the word inexistent is more a slangish word?

[emersion]

Feel free to send a PR to improve the second one. As @hd1ex said the first one is not a typo.