I have no problems with folks that do this.
As long as they do NOT teach that we HAVE to!
Romans 14:5
One person considers some days more holy than others, while someone else regards them as being all alike. What is important is for each to be fully convinced...
I agree no issues if brothers and sisters want to celebrate feasts and days most of the apostles and early Christians did. Your quote was one of two addressing the matter.
I know some here that do adhere and are solid Trinitarians.