If one is involved in a traditional Chinese martial art. We don't claim to be. Our art is a American art that was developed in Hawaii. We have established our own traditions. We ask no one outside of Kajukenbo to follow them.
We also use the title "Professor" and "Grandmaster". "Professor" is used pretty widely in Judo/jujitsu and Hawaiian Kenpo schools. The title "grandmaster" can be found widely used in Chinese, Japanese, Korean, and other arts.
In our Wun Hop Kuen Do branch they do use "Sigung" in the traditional Chinese way. Only a students teacher's teacher is addressed as "Sigung". So you have a instructor being called "Sifu" by his students, even though his actual Kajukenbo rank is "Professor". His students are calling his instructor "Sigung", even though his actual rank in Kajukenbo is "Grandmaster". I don't care for it. It's like trying to serve 2 masters equally.
In fact I don't really like all the various titles, sibak, simo, sisuk, sigung etc. If you want to use "Professor" or "Grandmaster" for the highest most senior ranks, fine. But the simple titles of "sensei" or "sifu" for teacher's is fine if you want to adopt a Asian title. I'm Japanese, raised in America, and have used a Chinese title in most of the years I've taught martial arts. Something like "sir" or "Mr." would be fine with me. Outside the classroom setting, "John" works too.