Is there a quick and easy way to switch between instruments in Kontakt?

I'm relatively new to Kontakt, and I have a question about the UI. Is there a way I can switch off the "multi rack" and just have a "single rack", so that I can try out a bunch of instruments that I've just installed?

The UI seems to make this a bit more difficult than it should be. I want to be able to go into my Library of instruments and just click on a piano or a synth and then immediately start playing it with my MIDI controller or the on-screen keyboard. But I have to scroll through the Libraries list, click the little arrow to expand the instruments, then double click the .nki file to load it. Then I double click another .nki file and it loads the second instrument. I figured out that I can drag a .nki file over onto the existing instrument to replace it.

I've just found the Database view, which makes it much easier to find instruments based on types/categories. (I also can right click on the header in the results and show "Bank" so I can see where they're coming from. That should be on by default.) Then I can drag them over to the instruments section to replace instruments.

It's just a bit fiddly! I want to be able to single-click on an instrument to immediately load it and start playing. Or navigate through the search results with the up and down arrows on my keyboard so I can quickly try out some different sounds.

I found the "Quick Load" option, but that doesn't help much, it looks like you can drag a selection of instruments in there to access them quickly as a shortcut. But if you double click them they still get added as a second instrument in the rack.

Am I missing a UI option to make this easier? I imagine this is much easier using the Komplete Kontrol hardware, where you can quickly scroll through different instruments. I don't have one of those unfortunately, so I'm trying to figure something out using the VST in my DAW (REAPER.) It would also be nice if there was a way to wire up the prev/next patch buttons on my MIDI controller (Nektar Impact LX61+) to go to the next instrument. (I can do it using REAPER's own presets but it would be a ton of work to set them up for every single instrument.)

Would appreciate any suggestions! Thanks!