When to create mini-dimension

Our main dimension 'account' has about 40 attributes - name, address, contact details but then a large number of other attributes about the account, e.g. customer type, segment, accounting type, account status.

As the other low-cardinality attributes are commonly used with measures, we broke them off into mini-dimensions. These are then key'd into an aggregate fact. There is no snowflaking as such - the account dimension does not include a key into the mini-dimension. Items such as the account contact details stay in the account dimension (which is not key'd in the summary).

Is this approach right? We now have a lot of dimensions and subsequently the main fact table has a lot of keys (not outrageous - 15-20). Users love using the summary as it is fast......but hate anything that involves the main fact. In fact, they would like as much as possible in the summary! (not high-cardinality items obviously).