MEGA65 hardware doesn't support it, and might not for a while, as it requires an extra BRAM. T100 based boards are unlikely to get support for it, due to this. So I'm inclined to just not implement it, since very little existing software (if any) depends on it.
LG
Paul.
Oh, then my memory modules (in my brain, I mean) should be replaced, I thought it's done by mega65-core already :-O