First of all, the Third Commandment is to "keep holy the Lord's Day", not to attend Sunday Mass. There is a difference. The commandment to attend Mass on Sundays and Holy Days is actually a Commandment of the Church. But this only applies to normal times, which we are NOT in.
No, there isn't a difference. The Church defines what "keeping the Lord's day holy" means, which is, to attend mass. There are exceptions to this, which can apply in times of emergency, which we are living through.
Second of all, "Even if one does not like the priest who offers Mass..."? Seriously? Are you really resorting to a straw man argument? I want to say something snarky like, "But my priest has horrible B.O. I'm going to stay home from Mass with my family." Is that why you think some Resistance supporters have left the SSPX? Personality conflicts and mere personal dislike? The priest just rubs us the wrong way? Come on, you know better than that!
This was not directed at you so I don't know why you're getting offended by it. I've known plenty of people who view the mass/faith in a superficial manner, based on the priest. My comments were for them. If the shoe fits...
Lastly, your argument would 100% apply to attendance at the Novus Ordo and Indult as well. "The Mass has infinite graces, it's the Sacrifice of Our Lord Himself, He will reward us for attendance, even if we have to suffer and "hold our nose" during various parts like the sentimental music, the Handshake of Peace, altar girls...
Absolutely it does not apply to the novus ordo or indult because these masses are 1) illicit 2) doubtfully valid, and 3) immoral.
My original argument is that IF the main problem with an new-sspx mass is one of PROPAGANDA during a sermon, then that is not a reason enough to "red light" them. Propaganda is not error or heresy, which are both part of the novus ordo (heretical non-mass) and indult (public acceptance of heretical non-mass). I define Propaganda as meaning indirect or subtle promotion/acceptance of new-rome's authority or to the political "let's a make a deal with new-rome" situation.
Once a new-sspx priest crosses the line into outright heresy - i.e. promoting V2, or promoting heresy, or any other modernism - then that priest/chapel should be "red lighted". Until then, the neo-sspx provides valid, licit and moral masses (in general). All of this must be decided on a case by case basis, but overall, the new-sspx cannot be written off as heretical...yet. Just my opinion.