New comment by johna23-lab on void-packages repository

https://github.com/void-linux/void-packages/issues/39232#issuecomment-1243044412

Comment:
Thanks for the tip i modified the file 
xbps-create/main.c

And changed this section

if (compression == NULL || strcmp(compression, "zstd") == 0) {
		archive_write_add_filter_zstd(ar);
		archive_write_set_options(ar, "compression-level=22");
-
But if i make the package using the "xbps-create" it uses the level 22 and i get much better compression, but if i make the package using the xbps-src and the template i get the "normal" (low) compression.

The idea is that you can choose the level of compression (as a new option) with the xbps-src, e.g:
xbps-src -lc (level compression) 22 pkg template