Thank you,
i didn’t realized the relative feature request had been completed.
From the modified code i suppose that a ‘;’ separator on the footprint field
should populate the drop-down menu with the footprint alternative:
in my case it doesn’t seem to happen, the drop-down contains only the first footprint item of the list. ‘;’ should not be a special character, so no escape sequence should be required on the db (MySQL)
Any idea?
Version: 7.0.9-7.0.9~ubuntu23.04.1, release build
same on 7.99
P.S.
Now i understood how the stuff is supposed to work 
:
in the schematic symbol editor, setup a Footprint filter for the valid footprint:
then when you place your database part the pull down menù is properly filled:
…noice!
P.P.S
the information about multiple fooprints is not recovered from the DB but from the schematic library filter, not what i would have preferred but i think i can live with it.