Since I already had use for it, I finished the macro (new version attached).
New term dialogue box contains:
Added to my active glossary as:
Next step will be to add a keyboard shortcut to duplicate the content of the source and target term boxes :).
Happy with a very nice solution to add conjugated forms. With only 2 term pairs I cover plural, masculine, feminine and neutrum. The differentiation is useful, since German neutrum nearly always corresponds with Dutch neutrum :). Using pipes here for stemming would throw valuable info in the AA process away.
Some day I'll try to generate plural, masculine, feminine and neutrum forms macro-wise.
Another example, just for fun:
An example with alternative target terms:
With great help from of user gglick in the Keyboard Maestro Discourse (https://forum.keyboardmaestro.com/t/easiest-way-to-align-2-collections/8372) I created a macro to align multiple source and target terms added to the New term dialogue box:
I'll add the lines to write this to a glossary later ...