OK first off the lab I work in doesn't do Chlamydia testing. We're a pretty small and specialised Tertiary care hospital, hence me saying that I do not think that we will be of great use for discussions!
The MLA question is a bit more relevant. 1 year ago the decision was made to not replace a Band 6 Biomedical Scientist with another but instead to take on 2 MLAs.
The justification was that our BMS staff had been putting up all the new work which was something an MLA could easily do.
Also our serology section was often left for a day or two so the BMS could cover another bench in times of staff absence. Now we have an MLA doing all the booking in which means we can run all our serology in an afternoon (thereabouts!).
From what I understand the powers that be are looking to encourage labs to employ relevant staff to the tasks that need to be completed. I don't really know how/if this works in a larger, busier lab because of the issue of supervisation. Overall it sounds like money saving excercise.
I would feel sorry for anyone who takes on an MLA post hoping to progress to BMS as this would reduce their chances even more.