AI Denoise - need a way to apply to multi-select and let it run...

You can easily apply Denoise to as many images as you want. 

In Grid View:

1. Select the images of your choosing.

2. Right-click one of the images and choose "Enhance."

or...

3. From the menu bar, choose Photo > Enhance

In the Develop view:

1. Select Images 

2. Click "Denoise" in the Detail Panel

It will tell you how long it will take so you can plan accordingly. 

Besides my job here at Adobe, I'm a professional theater photographer and routinely apply Denoise to hundreds of images at once. I love it! It has allowed me to use ISO settings I would never have used before. 

1) Add a right-click context menu to a multi-selection:  "AI Denoise (group)".  I'm fine with just picking the same settings for all of them!

It already exists (in both the Library and Develop modules). Right-click and use the "Enhance" option....

Denoise runs entirely in your GPU. It does not touch the CPU. You need to have a fairly recent and capable GPU, or Denoise will be unbearably slow. With a good GPU, it should normally execute in 10-30 seconds depending on MP size.

No one is stopping you from applying Denoise to all your photos - but that's not what it's intended for. It's also a huge waste of your computer resources. Denoise is for the extreme cases.

For "normal" ISO shots (anything below, say, ISO 4000-5000), there is no real purpose in Denoise. Standard noise reduction is more than good enough to deal with it. Eliminating noise altogether can not be a goal. It will quickly give the image a "plasticky" and unnatural look in most situations.

When running Denoise, do not delete the originals! It's an irreversible process, you can't go back to the original mosaic state. In other words, you'll end up with a double set of files. That can be impractical to manage.