Gidday Mike,
Look I think that the only real issues that you may have with this sort of lighting is heat build-up, between the tile and the fitting itself.
With respect to the Insulation, as long as there is at least 4" of clear ventilation space(air) around the fitting, I don't really think that you can go wrong.
The only thing that sets roof voids on fire, is when insulation is put over the top of and close to these fittings(aka lack of ventilation!). [Linked Image]