When implementing the changes noted before, you'll see that Formulas for controls only allow to enter data in "Initialize when ... Editing Record"
However, if you go to Custom Properties for the control, you can enter this key:
And it will take the formula for "Initialize when ... Adding Record"
It would be nice to find in the templates or code generator properties where or how ISD enable or disable this properties in the formula tab, but in the meantime this works.