If you have been in the habit of giving your aircraft to the MO and "letting them get on with it" you are putting yourself at risk. For if by using LAMS or LAMP the MO misses something and there is an incident, YOU the owner are responsible. You should have supervised the MO and ensured they were doing the work correctly using the appropriate documentation etc.
And that is what worries me. As a reasonable pilot but next to useless maintainer of mechanical equipment, I shouldn't be trusted with a screw-driver. It is ludicrous to expect me to supervise my highly-experienced and trusted MO.
In fact, in English law, there is likely to be a test of 'reasonable-ness', but that would take a few cases to end up in court to establish it, and that could take shedloads of money and time.
Owners are expected to have subscriptions with manufacturers for Service letters, and to keep updated on ADs via the GSAC website and/or EASA website which will automatically send all new ADs to subscribing owners.
Really - this is the first I have heard about this