SysHardener works fine even if not updated from 2018, however it needs some new tweaks such as disabling of Preview pane, more "Block outbound connections for process ...", option to unassign .xml files, and a few others. It may also require to simplificate the UI. With Windows 11 registry tweaks locations have not changed (its base is Windows 10), so all should work same as Windows 10. Instead, we may add some new tweaks for Windows 11 OS probably, but not yet checked.
About when it'll be updated, let me not say a date or time interval for now. I wanted to update it a few months ago but then we got busy with APIVoid and OSArmor (they take precedence since they are commercial). We still have some updates/news to share, wanted to do that a few months ago, but couldn't. I can say that if we don't have too many slowdowns/sudden, soon we'll announce some nice things.