I cannot find any references that would confirm that this attribution is correct, but there is certainly evidence that Bacon was an accomplished Arabist. Was he not responsible for a Latin translation of Ibn-ul-Haitham's treatise on geometrical optics?
In your article VI you quote Kopp and Darmstaedter as saying that one "Rodogerus Hispalensis" was responsible for the translation into Latin of Geber's "Liber fornacum". This translator seems to be otherwise unknown. "Rodogerus" is the mediaeval Latin for "Roger". "Hispalensis", of course, simply means "someone from Seville" or "someone who lives in Seville". Could it be that the publishers of the Nuremberg editions of 1541 and 1545 found a Latin translation by "Rodogerus" (Bacon), assumed that he must have lived in Seville (as that was where the leading Arabists of the early Middle Ages were located), and named the translator accordingly?
Is it too far-fetched to posit Bacon as the translator of some of Geber's works? Since Bacon was fairly prolific, a stylistic comparison with the Latin text of the Summa should be possible and might prove fruitful.