In Windows OS, the automatic windows defender may drastically increase loading times for your libraries, even if you have performed a batch resave.
This is because Windows Defender automatically scans all files and samples as they are being loaded into Kontakt.
To increase your loading times in Windows, you will first need to add your libraries as an exclusion in Windows Defender. Microsoft has an article available to help you get this set up.
Once the exclusion is made, you can perform a batch resave on your libraries and find a drastic increase in their loading speed.