He signed the checks as President which technically could be argued as an official act as all acts as President can be termed official acts but none of this will matter once the federal courts get a hold of the appeal the Bragg trial will be overturned.
IIRC——TRUMP HAD TURNED OVER THE DAY TO DAY OPERATIONS OF HIS BUSINESSES TO DON, JR & ERIC TRUMP.
IF it WAS TRUMP’S “SIGNATURE”, it would have been an electronic one or similar.
TRUMP WAS IN THE WHITE HOUSE THEN.