To bad it's an Electron app. I'm really RAM restricted …
Both had the same mail opened.
I'm using macOS 14.7.3, not 15. Don't know about Apple Mail in macOS 15.
At the very least it is quick and easy to try it out and see how it works for anyone else (I am interested in feedback from anyone else who has done a comparison).
…oh. Shame, that.
right-click->delete