Robert,
Like Jake said, the swapping out of symbols, especially *all* symbols, is not an instant thing -- it would chug for a few seconds, I would say quite possibly 6 or 7 on a large or complex plan with multiple xrefs. So it's just not a "quick flash" sort of thing. So that being said, let's look at how the existing tools can be tweaked. As Jake said, having the Plant Palette docked is very helpful, especially with the "Placed" option checked -- you can quickly click on Highlight to see where a particular variety is. After Right Clicking, you can then RC again to re-fire Highlight Plant, and click on a different plant -- here I see a chance to add something, it could echo to the command line the name of the plant highlighted. Also note that when you click Match Plant, and select a plant, it will be selected in the Palette. Here too though, I see that it could also be helpful to again echo to the command line the name of the plant selected.
Lastly, firing the Block Data command quickly is the old standby for identifying a plant in a complex plan -- this is something you could assign to a keyboard command to make faster.
Let me know if these seem like good enough workarounds.
--J