Open "new window" links from PWA in main Safari browser

With the newest edition of MacOS, Apple has finally introduced support for Progressive Web Apps (PWAs) - thank you!!

I have Gmail installed as a PWA on my laptop via Safari. In addition to the Gmail PWA, I'll have a "main" Safari browser window, which I use for general browsing (i.e., miscellaneous website browsing).

The problem with the Safari Gmail PWA is that when I click on links within Gmail emails, the link does not open in the "main" Safari browser. Instead, the PWA creates a new Gmail PWA window. That behaviour does not match the experience under the same PWA configuration with Google Chrome or Microsoft Edge, where links from the Gmail PWA open in the "main" browser window.

How can I get links within Safari PWAs to have the same experience as I get with Google Chrome or Microsoft Edge?