X11 functionality in wayland

I'm trying to prepare my Emacs configuration for distribution and I'd like to have it working under both X11 and Wayland. There're two things I'd like to have, one important the other mainly for me and I can do without and I could use some help from people familiar with Wayland.

[important] under X11 whenever I change the font size or the background color, I also write a ~/.Xdefault file. This way when Emacs starts its window has already the right size and color and there's no visual flashing. Is there a way for doing this in Wayland?

[nice to have] in development I can launch a secondary Emacs (that the window manager then maps to a different workspace, but this part is not too important). I have <f1> mapped so that from the main Emacs it launches the dev Emacs and focuses it (including switching to the relevant workspace). On the dev Emacs, <f1> would return and focus the main emacs. This way if I change the configuration <f1> gives me a dev Emacs and another <f1> brings me back after testing whatever I'm interested in. Any way to do something like this?