Will try to build the next version of SD tomorrow. (Patreon)

Outpaiting have some differences in the workflow that made it a little trickier to implement.

For example, you render the outpaint.

You don't like the result: You can't use the new image as a source by pressing render, since you want to use the mask from the previews version.

You like the result: You have to use the new image instead of the older one as source.

There is also some changes that need to occur under the hood, for now prompts run while messing around with the GUI. With outpaint it need to wait the result so it can merge with the original image and show it to you.

Honestly, out painting will probably will be a separate GUI in the future, but for now is simple enough to just add it to the main GUI.
Unless there is some unexpected problem with the code, it should be ready tomorrow.