I think the onus is on companies and NHS organisations to appoint or designate dedicated trainers for medical devices.
At this time any NHS employer can appoint whomsowever they wish as a trainer. There is no formal framework or structure; i.e. no regulation. My point being that currently, de-facto, individuals' job-title can imply, hence convey, competence of the trainer to those who are being trained. Employers, i.e. managers in EBME/Medical Physics departments, who may not necessarily be in a position to assess employees suitability, i.e. they may not themselves be qualified or experienced in this matter, can bestow these job-roles and titles.
Even if teaching/training under the "competency based training" banner were being provided, under the circumstances described above, should/would such trainers/training actually be recognised by those who are qualified to provide such training, e.g, manufacturers' trainers who are formally qualified/trained, that do this to guidelines such as those posted earlier for example.