Be far better banning halogen down lights than plastic CU's. I wouldn't personally fit a halogen if asked now.I agree, new installations should be LED now, perhaps we need the EU to introduce a ban on halogens for new installs.
Only yesterday, I was at a rental property sorting out half a dozen downlight faults in several rooms, 3 of them had burn-out plastic connection blocks and housings, in 2 cases I'd say it was lucky they'd not caught fire.