I think the KeePass behaviour is normal and not something we have any influence over.
As for the integration with the browser extension, I’m still not sure exactly what features you are looking for which are not already supported by Placeholder handling
Have you tried enabling the placeholders/references feature?
By the way, this most common of reasons for using references can be more simply solved by just adding a 2nd URL to the Kee “URLs” list in the entry. That way you only need one entry, form filling works on all the URLs and the only potential downside I’m aware of is if you want to use the primary URL within the KeePass interface as your starting point to load the website into your browser. If you’re starting from your browser (e.g. using a bookmark or Google search) that drawback is irrelevant.
There are probably still valid use cases of entry references but in the vast majority of cases they are no longer the best tool for the job.