SPO and Document ID Service (Bug, Communications site and what's coming?)

Hi,

Issue: In SPO (Modern) I have found an issue with the Document ID service when subsites are present. Enabling the feature on a site with sub-sites doesn't create the Document ID field and the "Begin IDs with the following characters" setting under the Document ID Settings is empty. Removing the subsites and reactivating the feature solves it and creating subsites post activation the Document ID service works fine on the subsites as well.  I'm aware on the recommendation on avoiding subsites as far as possible but still this is an issue that needs attention. This leads to my next questions...

...Looking at the Document ID service feature it hasn't been rebuilt/reworked for the "new" SharePoint which makes me wonder if there are any pitfalls and issues enabling the feature on Communications sites today? Besides, are there any plans to modernize the Document ID service to fit the modern SP and work better cross site collections or what's coming around this feature?

Thanks!

/A