Brian,

I do that type of plate for a commercial realty agency.

They must like them.

I've been making them, year-in and year-out, for at least five years.

Not only are the results similar to the Metal Photo process, there's the added advantage of including a color, other than black.

Peter,

Dye sublimated plates aren't meant for exterior use. If used temporarily, they should be good for a few months, but that depends upon how much UV exposure they're subjected to.

There are overcoats, i.e. Frog Juice and others, that can prolong the life of an image, but not for the long haul.