At risk of opening a can of worms here, but if i give you a level restriction and then a frequency change, I'd like you to make that level unless the next guy specifically says you dont need to - mostly because theres a good chance you will end up in someone elses sector! I know the rules say any clearance cancels previous etc etc, but it isnt inherently safe IMO. Ask for a visit to see us if you are based at manch pete
As rodan says tho, plenty of previous on this topic
LOA