Here is coreelec 21.1.1-omega. the kodi of it is:
CoreELEC:~ # /usr/lib/kodi/kodi.bin --version
Kodi Media Center 21.1 (21.1.0) Git:72f13fb388a529094b8d5b5274ed0e5f1a2af8da
Copyright (C) 2005-2021 Team Kodi - http://kodi.tv
I can’t find anything about play speed in this kodi, either the play speed in the settings of video playing, or the “Adjust display refresh rate”或“Sync playback to display”. Indeed, I can see it from the kodi of coreelec9.2.0
I can see the play speed in the settings of video playing of the kodi 21.2 of windows x64.