Open as Layer / speed of copy-paste

[Warren Baird]

The work that I do involves a lot of combining multiple photos on 
different layers --- in the Gimp, I simple open the base file, and then 
use 'Open as Layer' to open the other images directly as layers on top 
of the base image.

In Krita, the best approach I've found is to open the files individually 
and then copy/paste them onto the base image.   Is there a way to do 
something like "Open as Layer" in Krita?   Would it be hard to implement?

At the same time I noticed that copying and pasting images in Krita is a 
*lot* slower than in Gimp.   For 8mp images it takes a very long time to 
both copy and paste the images.    In the Gimp the copy is instantaneous 
(I think they are doing a lazy copy), and the paste is probalby 3x as 
fast as Krita.    Has any thought been give to speeding this up?

Warren