I’ve only known one bloke who advocated men’s rights. It was his opinion that the law is skewed in favour of women, to the disadvantage of men.
He was a lawyer and generally brilliant man. He had also left two marriages. Each time with toddlers.
Our family court puts the needs of any children first and has teeth. The rule of thumb is that the non custodial parent pays 40% of their income as child support for one child. Obviously a sliding scale with multiple children.
Now I’m not saying his anger and bitterness towards the Family Court and women was caused by his perception of injustice. Could be a coincidence for all I know.
My attitude was that his behaviour was appalling and no fucks were given. When it came up I would change the topic.