The supply of different cassettes has been dwindling. MY madness is to stick a twin check tab on the cassette when I develop the film, (and noting the number on my film notes) and if the fog has gotten too big when the film is developed, I fish out and discard that cassette.
Since many of my SLR cameras are Canons that get upset and flash an icon on the LCD if they can't find the DX code. I have been using strictly the metal cassettes with the DX code. I am hoping that someone will gear up to produce these before I use up all my stock. I don't have the patience to use tape and stickers to try and emulate the DX code.
back when I used the plastic ones, I found that the light trap often would start to leak on the side with the removable cap after not all that many uses as the film gets forced into the trap from that end.