No, it would not be necessary to have different rules. That said, the legislation in each jurisdiction would have to be adapted. So the Quebec legislation, the ORCR, should allow for this change. This concept can be applied across Canada for employers under federal, Ontario or Quebec jurisdiction.
You also mentioned risk management, and you asked how it would be structured. It is simply a side account that is virtually identical to the first one, which is a true trust. The only difference is that the employer would voluntarily put more funds into the new vehicle. Moreover, the employer could withdraw the funds later, but only if there is a surplus in both funds combined and a surplus that exceeds the recommended safety margin.
That is why it is attractive from the participants' point of view. The only time an employer could get its hands on the money would be when there was already a surplus and a cushion.