Originally Posted by kovidgoyal
You mean as opposed to viewing the epub with the viewer and then copying the unobfuscated fonts out of the temp files? Or running an epub to epub conversion with the debug pipeline option and copying the font files out of the debug directory. Obfuscation is a joke, and a pretty poor one at that. So while I will take reasonable steps to preserve obfuscation, there are limits to how many hoops I am willing to jump through.
Entirely your decision. I would just note that doing conversions using the normal interface of calibre is a bit different to the scenarios you mentioned.