Another item from the Addendum worth noting (under 8.1):
"The sponsor should ensure that the investigator has control of and continuous access to the CRF data reported to the sponsor. The sponsor should not have exclusive control of those data."

One interpretation of this is that a typical arrangement where a CTU hosts their own EDC system would be non-compliant (there is no local investigator copy of the data). It would be possible to modify an EDC tool to - say - save CRF PDFs on the investigator's local network but there are obvious complications of this approach.

It would be useful to get clarity from MHRA on this, ideally before they pay CTUs a visit with a particular expectation.