I have looked at the pain study. This was 15 people--interestingly, it started with 18 and they removed 3, a whole 1/6th of their study population, one because of being too sensitive to the heat stimulus. So Idk what that means for people who are sensitive to pain from heat.
The researchers had them rate pain from a heat stimulus, then did MRI with that stimulus before and after 4 day's mindfulness training. They were instructed that this was secular, but there were no interviews to ask subjects whether they themselves felt it to be spiritual. That would affect whether this is a pious practice or something else.
There was no sham meditation control group. There was a within group control of rest vs active meditation, but that doesn't rule out expectations of effectiveness. Some studies like this try to look for subject bias/placebo effect by asking in advance whether the subject thinks the experimental condition will have an effect.
There was a 40% reduction in subjective pain, on average, although the raw data is not provided. Mainly they were looking for fMRI correlates in brain activity to pain responses before and after meditation.
I would say, again, small study. Hard to say what it means. In regards to practical use for pleasure, if this study holds up in replicated trials by other labs, it means that people not in pain who use mindfulness meditation are able to tolerate heat with less pain.
It doesn't address chronic pain, and responses to one noxious stimulus are not always generalized to others.
So think about that-- is it a good idea, for pleasure, to mess with your pain response, which in the case of heat protects you from painful tissue damage? I'd like to keep my pain function fully intact, unless I have otherwise untreatable chronic pain.
Finally, even for chronic pain, I'd want to compare side effects of long term use of various modalities, in order to do a full hedonic calculus.