'ExtensionInstallForcelist with locally stored extensions

Values in ___\SOFTWARE\Policies\Google\Chrome\ExtensionInstallForcelist registry now can not be used to automatically install locally stored extensions? Extensions that can be acquired from google webstore work flawlessly and can be automatically installed just fine.

Can I specify a value like: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa;file:///__path_to_update_manifest_xml.xml and in the specified path I have an xml file like :

<gupdate xmlns='http://www.google.com/update2/response' protocol='1.0'>
    <app appid='aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'>
      <updatecheck codebase='file:\\\path\to\extension\file.crx' version='2.0'/>
    </app>
</gupdate>

which points to my .crx extension file? Would this approach work if I want a locally stored extension to be automatically installed and irremovable? I've tried this approach but it didn't work, maybe I've made a mistake somewhere, or is automatically installing locally stored extension even possible anymore? I know non-google webstore extensions are no longer allowed (https://developer.chrome.com/docs/apps/autoupdate/) but is this also the case for local extensions as well?

Resources looked at: ExtensionInstallForcelist keep blocking a local Extension https://chromeenterprise.google/policies/#ExtensionInstallForcelist