I wouldn't auto update from AUR but you can easily download a snapshot of the PKGBUILD of particular software you want from the Arch website and verify that it

I wouldn't auto update from AUR but you can easily download a snapshot of the PKGBUILD of particular software you want from the Arch website and verify that it isn't doing anything questionable (and fix it if it is) then build it yourself. It is a simple format and easy to review, it is rare to see patches or non-obvious build steps. Personally, I have a dedicated aur user with some aliases that grab a URL from a fifo and print it, download, and extract. There are also often packages that pull the latest version from git and can be easily updated to use release branches if you want. Because of the focus on upstreaming fixes rather than keeping patches you can also just build outside the package system and install to /usr/local and you will still benefit from the project likely having received patches to build on Arch (if they don't test it themselves). Even if not yet fixed upstream, any random issue you encounter usually already has a bug filed by an Arch user unless you are extremely quick about updating.