Hi,
Well, this is an interesting development. I decided to insert a field (Email) from the User entity using the "proper" method of inserting dynamic text i.e.

I then added the same variable to the template but by typing it in manually; which gave me the following template structure. As you can see, below, the text for the dynamic field looks identical:

However, when I tried to use the template; this is the result:
Variables added through the template interface:
Full Name Craig Harland
Email caharland@outlook.com
Variables added manually:
Full Name {User:Full Name;}
Email {User:Email 2;No Email}
As you can see, even though there appears to be no difference between the field references in the template other than two were added through the Power Apps Template Editor interface and the other two were typed in manually by yours truly.; in usage the fields added manually are not resolved.
Head scratcher. 😅
Craig
Hi,
Full Name Craig Harland
Email {!User:Email 2;}
Email with insert
As you can see the
Hi,
Full Name Craig Harland
Email {!User:Email 2;}
Email with insert
caharland@outlook.com