Consider this 6502 source code created by dasmfw

NUMBER_OF_BYTES_TO_FILL comes from a label (just like UDG_RAM a couple of lines later)

Unlike UDG_RAM, NUMBER_OF_BYTES_TO_FILL is not an address, it's just a quantity, but anyway, it appears in the created source code

However, if I swap to using a deflabel

then I still get the same equ created in the source code (now in the Used Definitions list)

but it doesn't get used in the code, I only see the raw number instead:

I'm not sure if this is a bug or correct behaviour as designed, but either way, it wasn't what I was expecting.