Howto use "New recording of" for SAP-Fiori Script-Update?

Hi all,
I want to use the UserPath maintenance mode to update my existing and running SAP-Fiori UserPath "A" after a patch on the SUT.
What is the best way to do that?

Because of the NL issue regarding content type identification (see also http://answers.neotys.com/questions/2246469-howto-replace-dynamic-parts-binary-post-request-content) I have to do the following steps to update the UserPath:

• I do a "new recording of" the working SAP-Fiori UserPath "A" with the name "B"
• at the end I walk through the wizard and finish it
• in "B" I change the content type of identified binary content to "Text"
• Save the NL project
• on "A" I start the "Advanced -> Update with a recent ... and walk through the wizard
• at the end I check the updated "A" and see that the content was not replaced by defined variables, BUT the variables in the header are still available

Please help me.
Niko