I was looking at differences in CATALOG behavior on the 41CX vs. the earlier models. The 41CX adds CATALOG 4 (EMDIR), 5 (ALMCAT), and 6 (key assignments), and shows byte counts on ENDs in CATALOG 1.
Anyhow, I happened to notice something that I thought was broken on the 41CX, but it turns out was unchanged from the 41C and 41CV.
If you put the value 1 in a register, say register 21, you can use "CATALOG IND 21" (pressing shift for indirect) and get catalog 1.
However, if you put the value 1 in a stack register, such as X, then press "CATALOG IND ST X" (pressing shift for indirect then decimal for stack), you get catalog 3. It appears that catalog indirect from the stack always gives catalog 3, regardless of the selected stack register.