Are the rules changing for getting CSA from a self employed ex?

My ex left with a neighbour now 7 years ago. I moved well away after he kept using the children to get at me, the girlfriend kept lying to my daughter all the time about things she said I did and my daughter kept defending what she saw (then 9) but my then husband believed the girlfriend. As well as keep putting up with the constant bullying. When I realised she meant more than our two children felt it best for us all to move away. When he sees the children he can’t even see it to buy them a magazine let alone help with clothing/school uniform when asked.

I have fought constantly through the CSA for maintenance of which I only get £20.00 a month for both of them. He is self employed and when challenged through the CSA always hangs it out as he’s says he’s getting his ‘book’s reaudited’ but always comes back with the same figures. I have know actual evidence but know for a fact that he has been working on quite a few new projects and does alot of work for McLaren racing where he can charge alot for.

I have heard that the law/rules are changing this month for seeking maintenance through self employed exes. Is this true?