Hi pg888,
Glad you have a solution that works well. I think the key here is that by assigning your investments to a currency that is not in the default position (top currency) it gives you the flexibility to change the exchange rate investment at any time later, and allows you to view your investments in any currency you want. This is a nice idea.
To answer your question about viewing the top-most sub-portfolio in a single currency. Yes, when you turn on "View / Exchange Rate Adjusted", all of your investments are converted into the default currency, using whatever exchange rate settings you've set under "Options / Currency Settings...", so as long as your exchange rate settings are all set properly to convert to a single common currency, this will work. This is the intended operation.