Reputable CD manufacturers demand that all the music on the said article has been 'documented, properly itemised and all 'dues' paid…
They usually have such as this in their terms and conditions…

'All contracts are subject to the Company receiving any necessary license to purchase, process or use the required materials
and / or to manufacture the products'

They won't make 'proper' CDs without clearance then?

The MCPS/PRS have similar terminology on their blurb…..

'If you don't obtain clearance for your use of copyright music, you could face legal action for copyright infringement
and may become liable to pay damages and costs.'

But anyone can produce a CD-R themselves (at home, in any quantity they can be bothered with) and avoid such legalities and any subsequent payments. No?