I think this gets to the nub of it. As far as I can see, in the 4 prose collections, there is ample evidence that the buddha makes active use of “logic” and accepts it’s validity in discourse.
I think that viz the undeclared there is again, ample evidence that the buddha critiqued then current philosophical views of mistakenly going “beyond the scope” of logic.
I think that it is incoherent to think that the buddha, or nagarjuna, denied the validity of logic or the possibility of knowledge, there was already a skeptical school after all, and DN1 and DN2 single it out as the worst of the lot.
so the question is exactly how and why the line was drawn, both in the phenomenological, empirical world of experience, and in the logical, linguistic world of thoughts about said experience.
we have a repeated list of what the buddha said didn’t/couldn’t logically hold; that entities could be eternally existent, that entities could be destroyed, that the person could be identical to thier body, that the person could be different to their body that the person could have parts both identical and non identical to their body, that the person could be something neither identical to nor different from their body, that the universe could be finite, infinite, have both finite and infinite parts, etc etc…
we have a repeated list of things that the buddha thought could hold too, that consciousness must depend on an object, that fire must depend on a fuel, etc etc…
we also have the beginnings of a sort of interpretation along the lines of fictionalism with regard to persons in SN5.10 SN22.85 SN22.90 etc that appears to be a development at the very tail end of the pre-sectarian period, and then pursued with fervor in particular by the Theravada.
it looks like nagarjuna, in reinstating the primacy of the undeclared tetralemma form, is attempting to return to an “original” buddhism, and show how the buddhist insight was not in fact confined only to (not really existing anyway) individual persons.
All that said I can still not really make much sense of nagarjuna, and am really still trying to martial the sutta material that could underwrite my reading of him.
tldr, the buddha critiqued logic only when it went too far, and did not defend complete skepticism but rather attacked it.