No helicopter has any natural roll with sideslips below about 55 to 60 knots, so no helicopter can be IFR certified below those speeds, in spite of autopilots that do all the work.
How quaint! Strange then that the EC225 minimum IAS in IMC is 30kts when coupled to IAS mode. Some day you will catch up on t'other side of the pond. (just like old times eh Nick! Even though an old thread, I missed it first time around!)