LE-MOB XLHU screen exit 1764 issue

Hi

I've implemented 18 RF screen exits already for customization, but have a problem with implementing screen 1764. It is supposed to pass table HU_HEADER_TAB as a parameter else it is not possible to display what was scanned by the user or pass it back to the SAP main screen from the screen exit. So now I tried to use the enhancement framework to add a parameter to the interface, but module DATA_TO_EXIT0764 OUTPUT does not have implicit enhancement options, therefore function module EXIT_SAPLLMOB_012 cannot be enhanced. So I'm stuck unless I get an access key to make changes. Did anyone have a similar issue and how did you resolve it without access key (I don't want to hack SAP code).

Alternatively, is there perhaps a functional way to validate if a HU was already loaded, so that it will disallow the packing HU into HU if that is the case?

Please see image attached for issue where I have to provide an error message if child HU already loaded.

Thank you and best regards,

Adrian Bruwer