sudo disable trimforce doesn't work
Other users have also reported the same issue. TRIM may not actually be disabled on macOS even if forced. In my testing on a 3rd-party SSD, I could never disable TRIM on High Sierra.

On another note, it might be possible to improve your boot performance by following a guide I posted back when I was having similar issues.

The gist of it is that re-blessing the boot partition, and resetting SMC+NVRAM may improve boot performance. To re-bless, simply go to System Preferences > Startup Disk, select the desired boot partition, and restart from there.