This plugin opens Gimp 2 layers in Gimp 3.
Since there is a discrepancy in xcf versions and Gimp 2 will not open xcf file (ver.22) from Gimp 3 this plugin uses TIFF format (which handles layers well).

In menu: File ➤ Export to Gimp 3 (new-instance)



This is what the file opened in Notepad2 (attached) looks like New-instance-Gimp.bat.


In Gimp 3, select layers to edit


Before exporting back, set the Encoding:




Edit Layers and Overwrite:


Now you have two options:
1. Just go back with modified layers to Gimp 2 (without preserving layer mode and NDE editing):



2. Also save as xcf for further editing only in Gimp 3:

That is very clever but also very Windows

Thinking about it for linux users, linux had workspaces (desktops) long before Windows and you can drag-n-drop between.



Gimp 2.10 on one desktop, Gimp 3.0 on another desktop. Dragging a tab or a layer from one opens in the other. Then it depends where you drop. In the canvas as a new layer or into the tools for a new image.

A little example: You will have to accept that I drag into the other workspace.

https://imgur.com/2NM96ey.mp4 Of course there are limitations, only one layer at a time, such is life.

edit: Missed the important bit, you do have to start one or the other with the new instance -n switch. Just for info that is kubuntu 24.04 and both are appimages.