Does allowAppInstallation make itms protocol invalid?

I put apps to download with itms protocol made page on MDM.

itms-services://?action=download-manifest&url= plist path on the MDM server.

I put an app A of App Store with App Store download URL onto the itms page, and an app A of Enterprise(Inhouse) app which is uploaded on the MDM.

Both are the same apps, although the Enterprise app layout on itms requires an ipa file and a manifest file to be uploaded on the MDM.

If we set NO allowAppInstallation first, it doesn’t allow to download the app of App Store, which quite makes sense, because it prevents the device to connect App Store.

However, the same happens to the Enterprise app.
I thought Enterprise apps don’t require App Store connection, am I right?

I know Managed Apps can push apps no matter if NO allowAppInstallation is set.
And also it’s no problem to download if we put the app on a server directly and get the direct path

Could you advise how we can download Enterprise apps on itms page *without* allowAppInstallation?
Does NO allowAppInstallation make itms protocol invalid?
Does allowAppInstallation make itms protocol invalid?
 
 
Q