Apart from the Night Riviera, I don't think there are any remaining trains in regular service with droplights. Nevertheless, vegetation encroaching on the loading gauge remains a Bad Thing. It can cause damage to trains, and can be caught in open toplights on non airconditioned stock (I have had bits of vegetation enter a carriage on a 455) or cabside windows, the latter being an obvious hazard to drivers who may have a legitimate reason to be leaning out. I recall travelling on a Chester-London Voyager diverted via the Northwich/Sandbach line, which seemed to have vegetation scraping alongside most of the way.