I also use it for the sign “retire” (or retirement) – it’s probably considered more of a Signed English or SEE variation since it’s initialized, but I believe it’s still commonly used around here.
third group, 9th sign-- the R with thumb extended-- I have been racking my brain trying to find a sign that uses that. Then I though, Duh... and did a symbol search in the American signpuddle, found all of one match, and that was a name sign. How do you evaluate whether that is truly necessary? Many people are "thumb signers" ---meaning they lazily leave the thumb sticking out even when it is not part of the sign/handshape. There are "pinky signers" too.
This is just my first read thru, and looked mostly at what is NOT a regular ASL handshape. That is the only one I questioned at all. I'll give it some more study to see if there is anything missing from the list... that is harder! Did you look at Stokoe's work to see what handshapes he included as required in ASL?
I have been looking at the Symbol Frequency in SignPuddle to see what handshapes would truly be necessary in ASL. What I did was I added symbols with high frequency automatically and then looked at the handshapes that had a low number to judge if the signs written could be written with or with a different symbol from my personal experience. Below is the list that I have come up with. I was quite amazed that there were only 83. Are there any handshapes that you feel I might have errorously ignored or overzealously added?