Can you have a dynamic appinstaller file?

Hello. 

Is is possible to dynamically create the appinstaller file through an API call?
I have multiple people who for various reasons are on different versions of the program.
The idea was that I could have an API work out what the contents of the appinstaller with versions being kept up to date through my database. 
I have created an API that returns the contents of the appinstaller and has version numbers set. 

I have an API endpoint https://myAPIserver/api/msix/AppInstaller?customerID=John&environment=PROD" 

Which returns: 

<?xml version="1.0" encoding="utf-8"?>

<AppInstaller

   Version="4.0.0.10"

   Uri="https://myAPIserver/api/msix/AppInstaller?customerID=John&environment=PROD"

   xmlns="http://schemas.microsoft.com/appx/appinstaller/2018">
<MainBundle

   Name="John-Live" Publisher="CN=John Limited, OU=John Ltd, O=John Limited, L=Manchester, C=GB" Version="4.0.0.10" Uri="https://myBlobStorage/package/PROD/4.0.0.10/John.msixbundle" />
<UpdateSettings>
<OnLaunch

   HoursBetweenUpdateChecks="0"

   ShowPrompt="true"

   UpdateBlocksActivation="true" />
<ForceUpdateFromAnyVersion>true</ForceUpdateFromAnyVersion>
<AutomaticBackgroundTask />
</UpdateSettings>
</AppInstaller>

However when I run the installer I get Error in parsing the app package.

Can this be resolved or is there a better way of handing multiple customers accessing different versions of the program.
I am trying to get away from a customer and environment specific appinstaller file.

Many thanks

John