Two things to separate here IMO :
1 st one is that KICK NRE & ANA 1.5 have been reported not working on MacOS version above 10.14, S.A team have explained that they were trying to get back to 3rd party developers to have them fixing it but that they can't promise that it will happen. You can read more about this in this thread.
So unfortunately, beside solutions like getting back to an older version of MacOS, having the chance to have an older spare Mac or even setting up a Hackintosh running an older version of MacOS on a spare PC ( which I totally recon, is not available to everyone and involves a cumbersome process & is time consuming), there's not much to do about this.
Now maybe it worth it to take the plunge if you can do it and if you are really in need to get Kick NRE or ANA 1.5 working for older projects.
Last thought here is that by the end of the day, it's all about some kicks & synth patches inside projects and getting back to them and replace your instances of Kick NRE & ANA 1.5 with Kick 2 & ANA 2 and doing some sound design again might be the easiest way to be back on track with your older projects. Agree it's frustrating and also cumbersome but it's more a mind set & acceptance thing I believe.
Which leads me to the 2nd point : are you still having issues to open and get back to these older projects with Live ?
Just deleting the AU Component isn't enough to fully uninstall KICK NRE or ANA 1.5, if you follow this post you'll find the instructions to manually remove ANA 1.5 files & plugins. I don't have Kick NRE installed myself, but the locations and procedure would be the same, you just have to make sure that you delete the matching plugins for Kick NRE.
Once done, you should as well clear your MacOS AU Component cache database ( note that all your AU plugins will need to be re-scan next time you start Live then ), this is explain in the previous post of this thread, but here it is again :
- In the Finder, choose Go > Go to Folder from the menu.
- Type ~/Library/Caches in the "Go to the folder" field. Press the Go button.
- Remove the "com.apple.audiounits.cache" file.
- Remove the ~/Library/Caches/AudioUnitCache folder
- Reboot your Mac.
- Next time you start Live, all your AU plugins will be re-scan.
Then you shouldn't have any problems opening older projects except the fact that the Kick NRE / ANA 1.5 will be reported as missing/not installed and greyed out and being inactive inside Live, you can then replace those instances with Kick 2 & ANA 2, keeping any Fx chain you add on those channels and get back to sound design or finding a new preset that suits your needs.
Can't help much more than this unfortunately, hope that's at least giving you some insights about a workaround solution