No longer have an ADR. Very rare for me to drive a wagon on the roads these days.
Still put trailers on bays occasionally if no drivers in the yard.
When I did have I had tanks and packages, all bar explosives and radioactive (the rare ones).
The rule on Shell was that the Company would pay (they arranged a course and you still got paid your salary) for your five yearly renewal. Bonus was you would get all groups that you held renewed, even though for petroleum spirit we only needed class 3 (flammable liquids) in tanks.
ADR not worth spending your money on unless needed for your job (or a job you fancy).
Whilst my ADR was still valid I did some hazardous waste work on a rigid through an agency, but the work was awful and the pay was poor (less than a £1 an hour more than non-ADR), so I soon gave that up, and when my certificate expired never bothered to renew.