Add support for variables in configuration profiles

Hi,
Please add support for custom variables in configuration profiles.
Currently we have to deploy configuration profiles as scripts by setting variables and then echoing the profile contents to a file.
Example:

#!/bin/sh

MachineName=$(/usr/sbin/scutil --get ComputerName)

/bin/echo "<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>PayloadContent</key>
<string>$MachineName</string>
</dict>
</plist>" > /private/tmp/profile.mobileconfig

sudo /usr/bin/profiles -I -F /private/tmp/profile.mobileconfig

This works now, but when we need to add variables to a configuration profile that can only be installed via an MDM server, the above script will not work.
I understand that the SCEP configuration profile already supports variables from Apple natively, but I need support for variables adding to profiles that Apple do not support.

There needs to be some kind of variable list that can be used in all configuration profiles and if the variable exists in the profile, PMM software will replace the variable with a value before installing the profile.

Reference link for context: https://www.amsys.co.uk/mdm-configuration-profile-variable-reference/