STHM (SHM) and automations - Options / Workarounds?

Use this workaround:
https://support.actiontiles.com/knowledge-bases/8/articles/8170-how-to-use-new-smartthings-home-monitor-with-actiontiles

Once it’s in place, you can use Webcore to manipulate the virtual switches instead of reading / setting SHM state.