Option to not set window position in X11
Vivaldi always tries to remember the position of the window and use that position the next time it starts or creates a new window.
That's probably the best (only?) option in Windows, but under X11, it would be nice to be able to leave the window position up to the window manager.
As far as I can tell, the position is just set in a call to XSetWMNormalHints, so just clearing the PPosition flag in that call looks like it would be sufficient.