If you washed the paper thoroughly afterwards, the paper should not be acidic. Acidic papers would cause fogging especially sulfamic acid and modern cyanotype combination (any other AFO using process would act similar imo). Sulfamic acid is a very strong acid, but at room temperature it acts slow, at 70C it acts as fast as HCl. But the slow action is the advantage, it does not damage the paper's fibers much like the other acids.

But you are right of course %1 would neutralize less alkaline content. If 1lt 1M SA solution (ca %10) can neutralize 14 papers, %1 might neutralize 1,4 papers (sheet size 56x76cm). But halfway through the life of the acid (0,7 sheets) the neutralization time would increase dramatically (almost doubles with some papers). %1 acid would work but for fewer papers, and I am concerned about the neutralization time and therefore consistency of the results.

It would not effect traditional cyanotype and VDB adversely, but it is a problem for alkaline sensitive siderotypes.

If I tested %1 SA for one sheet of paper (e.g. FAEW 300gsm), I would probably say it works but I am not sure overall it is a good practice, because compared to the second sheet in the same %1 the results would be inconsistent. I de-alkalise papers by batch, and %1 would not last for whole 2 sheets.