One of the requirements for an IFR approved helicopter is to have a cyclic centering capability in pitch and roll. A force trim system can provide that.
And there's a good reason for requiring the system - once you have trimmed up, it requires a force to displace the stick, thus providing the pilot with a cue in hand that the stick is being moved from trim.
Since even a small lateral displacement of the cyclic from the 'wings level' position produces a roll rate, which is probably slow enough to not be noticed until the bank angle is too steep to safely recover from by use of instruments alone, having a trim system is a good thing.
But we don't ever require it in all IFR training helicopters, like R-22/44, Schweizer 300, etc.
Pity.