We just updated the plugin for UE5.0, the update v1.5.0. should appear on the marketplace soon.
The update is about UE5 compatibility.
Note about ISMs. There is one new interesting feature in UE5, in some cases you can edit instanced static meshes directly in the level: move, duplicate and delete instances as if they are normal actors. We looked if it would be possible to extend mss plugin to snap instances but found that the editor won’t fire the usual “object moved” event in this case. So waiting to see if this is added in later versions.