Is there any way to make a compendium with the old BF patch notes? At the very least the card changes so we can have a better understanding of what cards had been balanced and and why.

Not sure you can dig those up from the files, but some of those patchnotes are public and easily searchable online.

Wiki:

http://battleforge.wikia.com/wiki/Category:Patch_notes

http://battleforge.wikia.com/wiki/Category:Patches

Public, may not work/be up to date

https://www.patches-scrolls.com/battleforge.php

 

Although there are a few patches on the wiki it's only a fraction of the total and you'll find that other sources like battleforge's facebook and patches-scrolls redirect you to pages that do not exist anymore. Even if there is some site with all patches it's not so easy to find. I'd like it if our community had easy access to this information so we could analyze card changes like the sandstorm nerf and mauler buff, changes in orb requirements for deep one and tremor, amongst other stuff.