Trim Enabler just had an update that adresses these issues and several others:
Trim Enabler 4.2
- Mojave Support: Fixed an issue with enabling Trim and installing the S.M.A.R.T driver on 10.14.
- Added a new tutorial for approving drivers on High Sierra and above.
- Added a new Optimize feature: Purge Local Time Machine snapshots on APFS drives.
- Fixed a layout issue causing labels to disappear in the Health feature.
- Fixed an issue causing Trim Enabler's privileged helper to not install correctly.