What happens at a chapel, by the members, is different than what happens DURING A MASS.
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These "scandals" of lists and of crazy chapel members do not affect the validity, morality, holiness or legality of the mass being offered. Therefore, you must attend such a mass, if that's your only choice. Being "offended" by people does not absolve you from your Sunday obligation, unless such "offense" takes place during mass, or affects the mass (i.e. if a priest were to require all in attendance to accept that a state governor has authority over catholicism or something crazy like that).
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The novus ordo is an offense against God because it mocks Holy Mass itself. An indult mass is a lessor offense, but still affects the morality of the mass, because by attending, you are openly accepting the novus ordo as "catholic".
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List taking, mask wearing or civil authority matters, even if anti-church, do not affect the Mass, but only the members of the chapel.
Things like this illustrate deeper problems with the SSPX, but I agree that this situation shouldn't put anyone "over the edge" if they weren't already avoiding SSPX Masses.
If you were OK with the SSPX before, you still should be.
If you were avoiding the SSPX before, you will continue to.