It is useful to have for "shadow" and "desktop" servers.
As per mailing list: client side window is too tall and wide, users will miss reporting important information unless we print it.
Done in r24765.
Client now prints this when shadowing my main display:
Xpra GTK3 shadow server version 4.0-r24738 64-bit running on Linux Fedora 31 ThirtyOne remote desktop size is 3840x2160 with 1 screen: :1.0 (1016x572 mm - DPI: 96x95) workarea: 3840x2133 at 0x27 SEK DP-4 (708x398 mm - DPI: 137x137)
this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/2519