I now have a solution based on @flokosiolās plugin for the sidebar.
However, I still had to edit the core to get the project number to display on the sorting page.
Would be great if a more flexible implementation could be considered for future releases. Iām sadly far from talented enough to propose a fitting solution.
You can modify the panel / sidebar with a hidden fieldā¦
Itās kind-a-hackish, but it worksā¦ 
- edit - The way I did it, was embedding a field that was not visible / doing nothing at all.
But it allowed me to inject some javascript - which added extra functions to the panel (canāt live without it - these days!)
I did forget about your hacks (although I use gallery grid in my blog) 
I recently updated Gallery Grid; it works now without delayā¦ and acts like a Kirby Default 
Itās a hack (inject a field which is not visible and attach some functions to it) - but it does the jobā¦
