One may attend Masses to fulfill the obligation at
SSPX chapels, but not “friends of the SSPX” chapels or “SSPX affiliated” chapels. One may still attend Masses at these latter chapels, but they will not fulfill the obligation; only the Masses AT SSPX chapels do.
However, if there is a diocesan EF Mass, one
must make reasonable effort to attend that. If there is not one, or if it truly would be a hindrance to go there, and if you are attending the SSPX chapel Mass out of a love for the EF and not to try to distance oneself from the Holy Father, then it is perfectly legitimate to go there, and it will fulfill the obligation.
In sum:
- Look for a diocesan EF first. If there is not one or if it would truly be a hindrance to go there:
- Ensure that you are going to attend the SSPX Mass out of a liking of the EF and not to distance oneself from the Holy Father. If this criterion is met:
- Attend Mass at an SSPX chapel, which fulfills the obligation.
OR
- Attend Mass at an SSPX affiliated chapel, but this does not fulfill the obligation.