@whale-av Yes, your example is fine because [value me] is global. It's the $0- prefix that forces me to use var(), which in turn prevents me from assigning to it. fexpr~ interprets "$0-holdCount" as "$0 minus holdCount" and therefore complains that there is no value named "holdCount".
Edit: Oooo, just writing that last sentence suggested to me that I name the value "$0holdCount" (omit the dash so that fexpr~ doesn't interpret it as an operator) but alas, fexpr~ rejected that too.
Edit 2: Oooo, just writing that first edit suggested to me that I name the value "holdCount$0" and so far I haven't been rejected.