This is tricky as AFC says that rrp's apply to "qualified" MTO's and some trusts are arguing this starts at MTO3. However no union has accepted this argument yet AFAIK and I would have said that qualified means not ATO or student. That said, what profile have they matched you to to get band 4? the only one I can find is "Medical Engineering Technician (Entry Level)" and if you've been doing the job long enough to reach the top of the scale then you shouldn't be at "entry level"