The central assertion of this paper:
Any viable F_QG must meet four intertwined criteria:
I'd argue is only partly justified. An argument for "Effective axiomatizability" is given, "Arithmetic expressiveness" is more or less self-evident, but the other two I'd say is given without justification.
Also the core concept of F_QG is defined in a very hand-wavy way. I'd like to see a concrete example of an existing theory formalized in the way they proposed in the paper. It's unclear to me how mathematical derivability from the formal system correspond to how laws of physics apply. Specifically mathematical logic is a discrete process, yet the world described by physics is generally contiguous. (Yes, there are ways for this to make sense, but they didn't provide anything for me to know how they intended for this to make sense.)