I did that rope-solo in the summer of 2002. It's a long day doing it that way. With two it won't take all that long.
Going straight up and then working left from the airy second belay station gets one to the same broad ledge above the dihedral mentioned below. But denies any good scouting on the Allis Chimney.
(Chauvain's Beta shows two pitches for what I call pitch three. Rope drag is not going to be all that bad if good sense is used and some directionals are used to get the rope off the rock)
But there are two endpoints for that bushy and very easy, third class, left-side variation of the third pitch that I have used.
The one that is at the left end of a bushy, grassy ledge has the climber passing 35-45 feet beneath the chimney, affording good visual inspection.
The other goes up a slanted dihedral (5.6) at the right end of the same bushy, grassy ledge. This offers no useful view of the chimney. It does however put the climber back on route.
If you have been using really long slings on the third pitch you will be able to get above the dihedral and a rounded block to a very spacious ledge just to the right of the chimney itself. This is the standard third belay station.
There's a broad steep ramp directly above the 3rd belay (5.8, if memory serves) and on your left there's an airy, hand-crack step-off into the base of the Allis Chimney. If you go up the chimney there will be ridiculous rope drag here unless the leader gets a directional into the far side of the chimney. (I elected to protect low right and high left shortly after entering the chimney)
It's a really nice climb when the weather is decent...I've been chased off it by lightning, that was pretty spooky!
"Moderate is not the new Low" - Chris Joosen, USFS Lead Snow Ranger.