Possibility to add next compression type like dwarfs and 7zip?

[fwn0]

I have some packaged portable applications with custom shell script for deploying and running these applications. I would say that the best option for my applications is using 7zip (best compression, but a bit slow for re/compression), dwarfs is nice, but for full functionality needs fuse.

Here are some examples:

Appimage: OBS-Studio_30.2.3-1.AppImage 177 mb (default compression)
Appimage: OBS-Studio_30.2.3-1.AppImage 142,3 mb (uruntime+dwarfs)

Wrappe: OBS-Studio_30.2.3-1.AppImage 142,4 mb (--compression 21 = zstd:level=21)

DwarFS: OBS-Studio_30.2.3-1.AppImage 133,3 mb (- l7 -C zstd:level=21)
DwarFS: OBS-Studio_30.2.3-1.AppImage 124,6 mb (-l7 -C brotli:quality=11:lgwin=28)

7zip: OBS-Studio_30.2.3-1.AppImage 127,7 mb (ultra - tuned)

The start times of the packed applications (unpacking and execution) are similar, but the time for compression is very different: between 2.5 min - 5 min, the best compression with brotli takes 28 minutes.

[Systemcluster]

Thanks for the suggestion! I'd be open to add runners with other compression types as optional features; or even replace Zstd with an all-around better choice if there is one. I don't have time to work on it right now, but I'd be happy to review a PR if you or someone else wants to add one or improve the existing compression.

(See #1 for a previous discussion on compression.)