So basically you tried the swap with a newer engine and sleeve and also a more unforgiving 5port setup, why was that relevant at all??! If you had said you had tried a stock RS12 3port sleeve in a jp black rs12 modified 3port engine and it didnt work then fair enough, cant see why it wouldnt though.
Ive measured it up and as suspected the timing of the boost and transfer ports are the same, the port sizes are all the same to. the only difference is the chamfered bottom edges of the boost ports which help smooth the flow of air and fuel from the crankcase and the long grooves to better guide the intake charge as it enters the cylinder.
The fact that asw used the same sleeve in the same engine as you and it worked makes me think your problem was down to another course. you should get reduced performance not drastic running issues as the modifications on these jp sleeves are more for flow not drastic timing adjustments.