Hi Mark,
In subportfolios, I've organize my watchlists by geographical areas or by sectors, and not by investment types. So in each subportfolio I have various investment types: indexes, mutual funds, ETF, currencies, relative strengths and yield spreads (both calculated with the "Create Investment from Investments" command), and so one.
This is the best organization for my needs, but it is not suited for the Risk/Reward Scatter graph type, which displays all the investments in the selected sub-portfolio. Yield spreads can have negative values, relative strengths and currencies are not relevant too, and these ruin the scales and readability of the graph.
So, for this graph type, it would be nice to have the option to select which investment types to display (with the ability for multiple selection) and which we don't want.