Thanks Dirk. That is what I ended up doing in IS 4.1 SP1 (but in 1 view) and appreciate that 4.2 will allow this to be done simpler.
I had been trying to avoid database views due to a longer release process.
I had assumed there would have been an easier way but the way you proposed is the only way I can think of given my knowledge of DI.
The only other way I tried was to use the SQL function but it failed with a constraint error on the MMT_LOCK table.