2006 Act companies are quite "secretive" insofar as the general public is concerned. Obviously the regulators and the tax man can get their hands on pretty much anything.
Separately, despite the current pitchforks it is highly unlikely that the UK government is going to legislate for the IOM or the Channel Islands. The constitutional relationship between the UK and the various islands is incredibly complicated and nuanced, and despite the wishes of the likes of Richard Murphy the UK isn't going to bulldoze legislation through destroying the communities there. The likes of the Cleaner and the Radio Virgin would like it to be otherwise, but it isn't ever going to happen