Giwi wrote:

I've heard that some pilots have the authority to descend to CAT II
minimums (RA100) on CAT I intstrument approaches. If this is true,
then how is the CAT I approach altered? Is the DH simply lowered?
Seems like this would result in steeper approach angles to make it
work out right. Alternately it seems possible that the DH is lowered
farther along the inbound course...but wouldn't this make it more
difficult to transition out of the cockppit and land?

This authorization has been around some 30 years. It is limited to ILS
ground installations that meet CAT II performance requirements, but do
not have TDZ or CL. As I recall, it is limited to Category A aircraft.

Having said that, why do you think the geometry would be any different
for a CAT II DA/H? it is on the same G/S, just lower and closer-in than
the CAT I DA/H point.