How to turn off Spamhaus for authenticated and / or selected users

We are using Spamcop and Spamhaus to globally protect our WHM email system. For the most part, I would say 99% of the time, this works really well. However, the mobile phone network and some fibre to the home IP addresses in our country are heavily polluted by spammers. My customers are being blocked by Spamhaus, and I can't keep on removing IP addresses from Spamhaus. it's a cat and mouse game and I will never win. I can't turn off Spamhaus for all users because then I will end us with a host of new problems. My question is: How do I turn of Spamhaus selectively for certain users? A great way in my opinion would be if I could bypass Spamhaus for users who have authenticated already. I generally trust or can locate my user base, and anyway, cPanel will warn me if limits are breached. Please help. This is a very difficult problem to explain to customers who have limited knowledge about IP addresses and the Internet. They think it's our problem, and yes, sure, it is, but we are in a catch-22 situation.