P: Ability to invert negative scans to positives (color and black-and-white)

There is an easy way to turn a negative to a positive using Tone Curves and you can turn this into a PRESET. So the thing is you drag the lightest point from the top right corner straight down (that makes everything Black don't worry) then you drag the darkest point from the bottom left straight up and voila you have a positive of your negative. Save it as a preset by only selecting Tone Curve and set it upon importing to apply to all the negatives or just use it after import and sync. 

Don't be confused with my technical credentials.  My MCSE is Microsoft Certified Systems Engineer.  I was a network engineer on the mainframe at Microsoft for 11 years.  At Microsoft I am retired.  Here, I'm with Adobe products as a tech support professional who works on anything but Light Room because Light Room only does a few things.  Light's and dark's and a catalog like in Elements.  I don't do catalogs but I do help with Element's editor technically.  That's why we help in Adobe Photoshop forums.  I was also on-loan to Adobe as a test engineer in 1992 when they began development on their first Photoshop so I know them well.  Light Room was made several years after and I never worked on it.  I might give technical suggestions but I am NOT a troll.  I have noticed that all of you argue among yourselves.  Maybe you are used to that, but I don't want to be involved with your arguments, okay?  I am not a troll.  Let's keep it that way.  See ya.  

Kevin -

I am not a troll.  I am a tech support professional for Elements in another log.  I got caught in yours by some kind of magic in our online software.  I am only making comments to yours.  You people told me you had a subscription to your program.  I do not.  Neither do I think I'm special.  I am only making a comments.  I don't pay money for mine and its is a full EULA.  I said I can do the same in my Elements that you are seeking and I suggested you buy Elements.  My boss has smiled at me for that suggestion.  Now stop calling me as troll.  My name is Steve.  I have a name.  And . . .  I will stop commenting because all of you are taking my good suggestions personally.  Later gator.  

Eric, don’t engage him. He’s a troll. He clearly does nothing but post negative comments around here, complaining about people he has nothing in common with. Most people who disagree can simply say so, and move on. Clearly he can’t, because he’s still responding—years later—with answers about a piece of software no professional uses. And his justification? “It was free.” Glad we have that settled. Maybe he will stop commenting now.  

@steve_lehman I have Light Room. I own it.

You own a license to use it. Based on the acceptance of the EULA you agreed to. 

So the product you have is not Lightroom Classic 10.0.  That's the current version.

I have Light Room. I own it. I don't subscribe to it. No need for me.  It came FREE with Elements, an add-on. 

It's a good sign that there is a market need when a plugin is developed that is commercially viable even after 4-5 years at a price of $100.  

I agree - I don't need a resource hog.  But software companies generally support more features in spite of the overhead required. 

This is an update to image processing that is meaningful enough that Nikon built it into their cameras, sells an adapter and lenses to facilitate the process, and still has a scanner that is widely used to scan negatives into a digital format.  

I can't argue with "make it work right".  But the latter argument, to me, does not feel right -- why would an alternative path through the "develop" steps necessarily be a significant resource hog.  But I think more to the point - EVERY new feature comes with some resource cost, that has been true since DOS and 8 bit machines. Software companies do not survive by being feature stagnant as a way to protect existing hardware, they survive by providing features people love and want, who then when needed add memory, disk, etc.  I now have two 24mpix and one 62mpix cameras, unthinkable 15 years ago.  I also have 256gb SD cards and a PC filled with 1TB SSD's. I don't want the status quo, I want continual functional improvement -- that's what we were promised for our subscription.