EUROCAE Working Group 110 and RTCA Special Committee 237 are close to finalising Minimum Operating Standards (MOPS) for offshore HTAWS: I am acting as Secretary to these groups. The alerting envelopes will largely be based around those published by the UK CAA in CAP 1519.
Once the groups have met next month (virtually) to conduct an internal review of the MOPS, they will be issued for public consultation, with the aim of publishing the MOPS in March 2021.
Leonardo has announced that it has implemented some of the CAP 1519 offshore modes in its latest avionics software update to the AW139. Although it seems that the low energy warning provided by Mode 7 is not yet incorporated. https://www.leonardocompany.com/en/press-release-detail/-/detail/17-07-2020-leonardo-aw139-s-capabilities-further-enhanced-with-new-avionics-software-release-and-kit-certification
This table has been presented a number of times by the UK CAA. It shows the additional warning times provided by Modes 7 and 3B, which warn of a low energy state on approach (Mode 7) and loss of airspeed on take-off (Mode 3B).