We've seen a variety of turbine wheels in them and there are a few turbine housing sizes.
No, there is no 97/92mm. There should be housings sizes available up to 36cm for the 97/87 turbine.
It also seems like HT60 87mm flows much worse than HX60 87mm.
I would say that is an accurate statement, though I wonder if it is more the housing rather than the turbine itself.
The HT3 exhaust housing entry port size is pitiful compared to the T6.