>
>
> Maybe you're aware of this and could spare me some time (and I don't have
> access to emacs right now): why the buffer "flashing" is a non-issue for
> standalone emacs? I mean, it also has to show something at the very
> beginning, while still loading the initial buffer.
>

Would reverting your create-after-visiting fix and merely creating the new
frame with an initial empty tmp buffer would fix the "flash", at least to
the level of standalone emacs?