P: Bring back the ability of Enhance to run in the background. (LrC)

Two versions of a Nikon NEF file shot at ISO 64, the same processing edits except for denoise, a cropped area of 1200 x 800 pixels. One is the former Enhanced-NR DNG, the other is the new non-destructive Denoise.

Which is which and how can you tell?

That sounds all logical, but what have you done differently on the qualitiy of the denoised photo? With 14.3.1 I get a wonderful denoised, sharp image with fine details that looks like a 100 Iso shot but is a 20000 Iso shot. Now I get a mushy, unsharp shot with lots of detail missing. It looks as if there has nothing happened. If you can show me the settings to get the equal quality  as with the dng version (and this is for me a One Click action), then please feel free to show it to me. I am more than unhappy with the crappy output of the new process and rolled back to 14.3.1 and it seems I sadly have to stay there for a long time. The 14.5 update seems did nothing to that problem. How long do I need to wait to get back a working high quality Denoise and the other new features in ONE Version? If I have to keep the old version just for this reason it seems there are other Denoise programs with less issues.

Increasingly, the vast majority of our Edit features are running ML models, and many of these models are currently designed assuming they can take over the entire GPU (since they will be the only thing running)."

By @KrishnaMaithreya 

I reread this comment and this part stuck out to me -- this is a terrible assumption to make. If this is the resource usage that is being assumed for current and future features you need to go back to the drawing board. You can't just blithely lock up the users' program when they use every feature. Is clicking "Auto" going to take 5-10 seconds in the future as AI adjusts the exposure sliders?

@KrishnaMaithreya this sounds like an engineering issue that was entirely Adobe's fault, whether by laziness or poor assumptions made by the product team. As highlighted by @ExUSA this also fails to address other concerns that this broken process causes like the inability to determine where this additional data is stored, the removal of the original DNG process, etc.

As a software engineer myself I understand that this is not an easy fix but saying that it's not worth the effort to fix is a really bad move. Surely there's a bunch of things in PS that are clunky legacy items, but you maintain them because people's workflows and processes require them right? It's the same here, except you don't show the same respect for the LR users.

This is a solved problem. Databases use record locking and all the developers need to do is lock those photos (maybe put an "in-progress" badge on them?) And they could also lock out other AI/ML features if its that much of a performance hit.

This explanation doesn't address the many other problems:

removal of the dng option

removal of the pre-application amount setting

inability to schedule denoise for later calculation

multiple bugs, many of which I have reported

Unfortunately, it seems like UI and workflow design are just not priorities on the Lightroom Classic development and product management teams. Please, PLEASE stop making your priducts worse when you change features.

I use a Mac book pro M4 Max with 48GB of RAM. The demoise is quick because of the processor but depending on the image it takes 5-10 seconds each. 
I denoise every picked photo I choose to edit. I usually edit only about 10-15 pictures per session but no matter the iso, even at iso 50 and outdoors, I use denoise. Somehow, it provides more detail to the image.

Although few images are not a problem to have to wait a few seconds, I still find it annoying that it won't work in the background.

My computer, and most of the newer computers, could easily handle the denoise processing in the back without slowing you down. There is no speed increase between the old and the new denoise processing, so, why remove it? 

Different people have different workflows. I'm a product photographer and I use pretty much every photo I take, and every one gets denoised. In my workflow there aren't any missed shots to cull out and I don't have to worry about finding the hero pic.

Computing has strongly skewed toward asynchronous operations as hardware has gotten more powerful. Synchromous, modal processing that locked up the UI would have been tolerated 30 years ago but is ridiculous today.

@drtonyb There's zero reason to waste compute or storage by denoising first. You may edit multiple variations of similar images and only see which is the best deliverable after basic edits are completed. As we're clearly seeing from this thread, Adobe knows very little about actual workflows. 

@ronb2 

Thank you for your comments on a professional's workflow. I do agree that locking up the UI during time-consuming processes like batch Denoise is a real problem that needs to be resolved. The workflow you have outlined is to batch edit first, then denoise. This is counter to the recommendations from Adobe that Denoise should be done first to avoid or limit AI Settings Update requests. Adobe needs to do something to fix this situation.