How to get Singleton modified timestamp

There are some older threads on this topic and I would like to know if there is any news on this.

It’s easy to filter for _modified timestamps when I ask for collections, and I thought this would work the same way with singletons. But there is no _modified when I retrieve data via the REST API from singletons.

What can I do to determine if there have been changes to a singleton.

I tried to recreate this with v2 and get the _modified field.

can you elaborate on this?