BRS in a twin?? There would be little benefit and more weight as the shute would have to be bigger.
More weight means less single engine climb performance so the only benefit would be single pilot incapacitation and maybe structural damage.
I believe the Cirrus uses the undercarriage as an inherent part of energy absorbing structure and landing on water with no forward motion can lead to broken backs.
So not sure I would use one with an engine failure over sea.
Pace