The requirements to upgrade from general to master falconer have changed recently. I have not seen these new changes posted anywhere, so I will post them here.
Here are the regulations that have been basically standard.

173.2
(6) Master Falconry license. Master falconers must:
(i) have at least five years of experience in the practice of falconry as a licensed General falconer or the equivalent; and
(ii) have possessed a raptor for at least 3 years of the time specified in subparagraph (i) of this paragraph; and
(iii) provide written recommendations for advancement to the Master license from three Master falconers who have evaluated the General falconer in the field to ascertain the candidate's level of proficiency in the sport of falconry and the skill and ability in the care of raptors commensurate with the activities and responsibilities of a Master falconer; and
(iv) be approved, in writing, for advancement to the Master license by the Falconry Advisory Board.

The falconry advisory board has added their own requirements now. I’m not sure where the legal authority to do this lies, but they will not upgrade you and will consider your request denied unless your written recommendations include “detailed descriptions” of the following:

• The species of raptor(s) the general falconer has flown
• The appearance and general heath of the raptors in the general falconer’s care
• A description of the raptor handling skills of the general falconer
• The ability/success rate of the general falconer’s raptors to take wild quarry
• The apparent dedication of the general falconer to the raptors in their care and to the sport of falconry.