pdf/ps can easily be created in a way that data for text and qr code fields are easily in plain text. seems like yall focusing too much on the higher level tools instead of what's right in front of you.
We also render shipping labels in PDF, and we have to be VERY strict with that. But we're still not touching that, as that process is not at slow and problematic as the invoicing one.
the end result when you open the file is still a regular pdf. it's just encoded with some areas unpacked