So I went ahead and upgraded to WLP 6.0. During the installation, it indicated I needed to update a number of items through the extension manager:
Community.components; visualizers; indicators
Strategies.ActiveTrader
MS123.PosSizer.dll

The text indicated that these would be available - They are not!!! So if you are on the fence regarding the upgrade, you may wish to wait until this gets resolved.

I'll give this a couple hours to see if I missed something before I file a support request.

You must download these from wealth-lab.com, just as the installation message indicated. Go to Extensions > Get Extensions, download the wle files and install them.

I obviously mis-read. Thanks for the clarification. It does work as you indicated.

I presume at some point in the future that these will be downloadable through the extension interface, rather than download, then drag & drop.

No, not going to happen - this is by design.

It works (and will work) like this:

a) You can download and install Fidelity-Supported Extensions without going to wealth-lab.com. Almost all of these are included with the installation with only two exceptions: Extra Performance Visualizers (Analysis Series & Monte Carlo-Lab) and the Heat Map Visualizer. (Another one is coming in about 5 or 6 weeks).

b) All other extensions, you have to "go shopping" at wealth-lab.com. Most of these are not "Fidelity-Supported".