This is not about the driver manager. WinPE import is performed by bootwizard. Hourglass is shown either bootwizard is running, or winPE import task exists. If it fails - it will be activated by daily schedule or you can force it by selecting any preboot image rebuild (there is at least la in image available).
If you want to execute it manually, you can try to run the following command:
bootwiz.exe -install -q -os WinPE10 -x86
bootwiz.exe -install -q -os WinPE10 -x64
You can try to invoke it by task and check NS and bootwiz logs.
There is a BootWiz.log (e.g. at "C:\Program Files\Altiris\Deployment\Logs\Bootwiz.log") containing command lines that BootWiz was called with like these:
2020/08/18 12:57:37 I: Command line: '"C:\Program Files\Altiris\Deployment\BDC\bootwiz\bootwiz.exe" -install -q -os WinPE5x -x86 "C:\Program Files (x86)\Windows Kits\8.1"'
2020/08/18 12:58:40 I: Command line: '"C:\Program Files\Altiris\Deployment\BDC\bootwiz\bootwiz.exe" -install -q -os WinPE5x -x64 "C:\Program Files (x86)\Windows Kits\8.1"'
Also, if BootWiz cannot import WinPE (ADK), then some error message should be logged there.