External Forms and default values

Case : How far can you set default values when using 'external forms' in action steps

A Form is filled in, contains field called 'Field A1'.
The process has 2 Action Steps, each holding an external form (they are different forms).
We want to pass on the default value from the baseform, to external form A, then from external form A to externalform B.

This is not possible !

The externalform B, has only 1 baseform; being the Form that started the ticket. You can't select the baseform. Alternatives:
- Do not use external forms in the process.
- Let the Step's actor change the Form (using Next steps : Edit Request Form).

example: http://dev.ssp7.smt-x.com/Forms/form.aspx?id=270
Ticket : 2145
Schematic