I seem to recall that UK CAA started a research project on high level floats, but it was taken over by EASA and is still lurking in their corridors of power.
There is a lengthy report here:
https://www.easa.europa.eu/rulemakin...inalreport.pdf
It also gets a brief mention here:
http://www.hse.gov.uk/aboutus/meetin...anoiac1201.pdf
Whether anything will even happen though...