I’ll chime in with my observations. I much prefer the look of Pd/Pt prints developed with hot (100F) potassium oxalate. I’ve used citrates (ammonium, Na and K) and the prints lack a subtle “sparkle” that I get with warm or hot potassium oxalate.
As for clearing, this can be very paper specific. For example, “Cranes 90lb Wove Cover Stock” which is very likely exactly what B&S sells as Platinotype clears very well in citric acid/warm water. This Cranes paper has undergone obvious changes in the last few years, but despite some experienced Pt printers disdain for this paper it is still a good paper IMHO.
Whatman 130lb hot press watercolor paper (a real favorite of mine) clears very poorly (slow) in citric acid. Interestingly, it clears very rapidly in EDTA (Na2)/hot water. Note that in this case, having the disodium form of EDTA for clearing is important. Disodium EDTA is acidic, while the more easily available tetrasodium EDTA is neutral. EDTA sold as just “EDTA” is almost always tetrasodium EDTA, which in my experience is not as good for clearing.
Of course someone will now post a completely different opinions or preferences re: papers, clearing, developers, etc. You have to experiment to find what works for you, your papers and process.