The question about having sex with your wife is one I have thought about also. The general consensus seems to be that it is a good thing as it strengths your relationship with her and gives her support through this time.
On the other hand, agreed sexual abstinence is also refered to frequently for a complete reset of the brain and attitude toward your wife and sex. Terry Crews and his wife did a sex fast and posted a video on it.
My Hard 90 has my wife and I in different rooms for now. So, a sex fast was enacted with no thought. If she were to desire connection I would likely comply, but I don't know if my body would go along with the plan. But ultimately, the decision is hers to make.
For me, I like to rely on Biblical guidance and in this regard the guidance is (1) to refrain with agreement and (2) not neglect the needs of each other. In other words, if she desires to make love she will have it. Otherwise, I will continue with the fast.
The problem with PMO is primarily the porn leading to fantasy relationships that replace the need for a real life, flesh and blood person. Secondly, the problem of masturbating to porn or porn thoughts and edging leading to either PE or DE. As I understand it, orgasm is only a problem when it is a result of the prior two conditions. With your wife is the proper context and is not problematic.
I hope this helps.