Amongst the various issues to be considered, a key point is the implications of the proposed (largely) blanket minimum height of 500ft, rather than the existing UK 500ft from person, vehicle, vessel, structure, rule.
In a helicopter in sparsely populated, rural areas it is often possible to fly safely and legally at say 300ft - 400ft, to keep beneath a say, 500ft cloudbase, usually by reducing airspeed and picking the route carefully ahead. Such flights would be illegal if our 500ft 'away' rule was superceded. The reality is that for VFR heli ops in poor weather it is impossible to know what the minimum cloudbase will be along the entire route. With a minimum 500ft height rule, many more VFR flights will not go ahead if the new rules are to complied with.
Will there be increasing pressure to keep that minimum 500ft height in poor weather with increasing risk of ending up in IMC? Probably.
Two other points. Is there not a strong case for helicopters to be treated differently to aeroplanes, which do not have the ability to slow right down and manoeuvre, to comply with the existing 500ft 'away' rule? The thought of a PA28 flying as above is very alarming, yet the rules do not differentiate.
Secondly with regard to ICAO integration, the unique circumstances of the UK should surely be considered. We tend to have poorer weather than much of Europe, being exposed to more Atlantic frontal systems, whilst we also have large areas of the country which are sparsely populated.
Seems this forum is an ideal debating platform for just these sort of issues.