For those with windows, I was having very slow loading times on loading either Kontakt 7 or Battery 4, and Maschine in multiple DAWs and standalone. I have been doing some "house cleaning" recently with clearing out old and unused plugins, samples, apps etc. I decided to give CCleaner a go and see what it found with the registry. I made a backup and let it scan and fix everything. I only noticed it cleaning up entries for apps that were no longer installed. I have no idea exactly everything it did, but NOW anything NI loads very snappy in Reaper. I tested with multiple projects. My jaw was on the floor.
I did need to fix a few plugins and apps after, but I did not touch or run Native access or plugin settings AT ALL. It just worked. I just want to throw that out there as an idea for those with similar issues.
Peace