I was also caught unaware by the scan Manager discontinuation when I upgraded to QBDT Premier Plus 2022.

I use this feature all the time.  I am a contractor, but used to work in software for manufacturing.  1st rule, never take away a feature.  My company that I worked for in the 90s was offering this to our clients then!

I am just guessing here, but either the provider of the scan software is either no longer offering and/or supporting it, or they wanted more that QB was willing to pay.

I do a lot of importing of PDF documents and also print to PDF in windows using Microsoft Print to PDF.

I have set up a folder system under my QBPdocs/Attach folder to save or print or scan pdf files to.

The trick was finding a scan software that was affordable and minimized the pain.

I found a freeware program called NAPS2 that fulfilled my needs.  It can perform most of the tasks most scan software can provide and configured to auto save and name files.  You can configure each users copy to save to a file path with a file name and date time detail and auto increment count suffix. It works perfectly with my Epson GT-S50 scanner.

It doesn't save to the ATTACHMENTS record in QB, but by clicking on COMPUTER in the ATTACHMENTS screen you have access to the directory you have scanned to and can select the scanned file.  I do a descending sort by Date Modified and the last file scanned is always at the top.

Not a perfect solution, but someone smarter that me could probably make an integration in to QB (maybe even Intuit!)