Responsa do Powtórzonego Prawa 24:3

Ergo, if a Jew then comes and blackens it again, that would be a case of double indecision (‘doubt’)²⁰⁸See the exceelent review by Rabbi Moshe Koppel שליט"א “Resolving Uncertainty: A Unified Overview of Rabbinic Methods” [email protected], where he writes:“Roughly, if a particular prohibition holds only if both conditions A and B hold, and in fact, both A and B are in doubt, then we can assume the prohibition does not hold.” There is a doubt if it definitively needs to be black and a doubt about applying a second coating.. In my humble opinion, that resolves the understanding of the Magen Avraham. Nonetheless, practically, my inclination is to be stricter, specifically to that of the Rambam who was the first opinion quotes there in the Evehn HaEzer, that obviously the halacha is as per Rav Akhai”- this is the end-quote from my journal on the Magen Avraham.