I don’t believe in canon. I just watch the movies I like and ignore the ones I don’t.
That’s essentially just saying your head canon is whatever you watch. It’s basically the same way I feel, since the official canon was messed up by the prequels and special editions anyway, it’s just easiest to watch the OT and not worry about the rest. TFA is also in my own personal head canon, and while I enjoy R1, I’m not super comfortable having it as a part of my personal canon. I can’t really articulate why, but it’s probably because Star Wars is just such a good jumping-off point that the information presented in R1 is entirely superfluous. It’s also tonally way more serious than the OT and TFA, so it doesn’t fit in as well.