Lightroom: Make preset previews larger

Thanks for the reply, John! The problem is that it can take quite a while for a number of presets.

As an example, I have a number of Black and White conversion presets. When I have an image I am considering for conversion, I'd like to be able to simply mouse over all of my presets and see a preview. This can make going through tens or even a hundred presets a reasonably easy and enjoyable task. The fact that is not a perfect WSIWYG preview is fine, I just want to see the *imperfect* preview a bit larger!

Now consider doing the same task in the workflow you suggest. It takes these steps:
1. Click the first preset
2. Wait for preset application to render on the full mage
3. Command-Z to undo
4. Locate the preset in the list and click it
5. Goto 2

Not only does it take significantly longer to go through this workflow, it takes quite a bit of eye-hand coordination to do it at full speed. You have to keep one hand on the mouse and the other on the keyboard for undo. You also have to remember your last preset so you can go to the next one in the list. I can certainly do this, but now my brain is engaged in the mechanics of plowing through the LR interface, not looking at my image.

I have found that I can extend the left Develop panel to about half the screen by holding Alt while dragging the divider bar. Unfortunately, the preview part of the panel stubbornly refuses to size vertically, leaving a small preview with a huge amount of blank space to either side. When this panel is much smaller, the preview knows how to size itself horizontally and vertically; that functionality is there, is just seems to be artificially limited to a certain maximum vertical size.

I can understand that making a larger preview can be more CPU intensive and may not be for everybody! The extra-wide panel functionality is already hidden with the Alt key, so an extra-large preview would already be hidden from non-power-users.