I think there are situations where consciously choosing to follow a social convention against one's "natural" inclination (which I think is a type of masking) is a good idea. For example, if someone has recently experienced a death in their family, I might think twice about making death-related jokes, or even bringing up the subject of death at all. I don't think these rules are inviolable; with the right context I think humor can help with grief. But I think it requires a level of intimacy with the person grieving and their relationship with the deceased, and thoughtlessly saying any thing that comes to mind can cause fresh hurts for someone already hurting a lot. That's a rule that I consciously try to follow and think very carefully before I break it.
There are other rules that I will willingly and gleefully break because I think they're harmful, e.g. "It's [unpatriotic / blasphemous / rude] to criticize [the government / church leaders / authorities]". That rule is bad and exists to reinforce the power of people who already have power, so I deliberately try to break it, and I try to catch myself when I find myself unintentionally following it.
I think a lot of "just mask harder" advice comes down to people's (well-founded or otherwise) belief that a certain rule should be followed, sometimes without question (I often find this axiomatic take explained with some variant of "that's just the rule"). I like learning about the rule even if I take the implicit recommendation of following the rule with a grain of salt, but I do find the implication that rules have to be followed because they're rules tiring.