Yup, that's right.

(1) With the canister removed and starting the engine with an external start fuel source...
Since the powermax can has a clunk, you'll need to invert it. Any other canister without the clunk will be right side up. If you're ever unsure, just pull your trigger valve and check to see if you get liquid. I suppose you could get an overly full powermax canister and get liquid when inverted, but that shouldn't happen for long since the clunk will soon be surrounded by gaseous fuel. The engine should only ever see gaseous start fuel...

(2) With the tank on-board and starting conventionally...
Use the powermax can right side up (and a clunk-less canister up side down) to fill the on-board system. If you decide to give it a shot while the engine is starting and you think the on-board tank is low, use it as above in (1).

The point is...
If the engine is starting off the internal tank, the tank is suppose to be oriented such that the outlet is at the top or such that the gaseous fuel escapes and not the liquid. To fill that on-board tank obviously you need to extract the liquid from the external canister (powermax: right side up, camp stove canister inverted), but it runs to the bottom of the internal tank and boils to again provide gaseous start fuel to the engine.

As an added benefit to the external config, you'll notice your start fuel will last much longer. This is because you never feed from the liquid fuel, which continually boils off to produce the gaseous content at the top, which is much less dense.

I'll put together a clearer picture and post it here once I'm back from Whidbey. (you coming by the way?)

Kelly