You do not need an SFI lower containment device until Pro Mod, Alky and Fuel classes. Otherwise you just need a diaper, NOT an SFI one. So in theory you should have zero issues with you expired SFI device.

According to the newest rulebook you do not need one unless you run Advanced ET, S/G, S/C or S/ST and Pro Stock, all non SFI required. Otherwise I don't see anywhere it is required other than those, and the aforementioned pro and alky classes.