Is your feature request related to a problem? Please describe.
When using the AiService, all user messages will be used as a template.
This cause issues if the message is not a template but still contains template variables.

Describe the solution you'd like
Having a way to specify that a message is not a template, or having the template mechanism not failing if it cannot find a parameter.

Describe alternatives you've considered
None.

Additional context
A way to choose the template separator would also work even if more fragile.