Firstly, thanks for creating the fix mapping of variables for the webapp Templates. Hope it launches for Mobileapp soon.

The contact fields that will be mapped to a template variable will be static/same/fixed always. So I think they should be fix mapping at time of creation only or laters. Currently choosing each field individually for each variable is almost the same as typing the data from the fields. And i observed that blank fields are not shown/allowed to map; for this you can also throw an error message for fixed mapping empty/blank contact fields