That would be useful for people with hearing loss or just someone working in a very noisy environment.
Well, I don't have a 121GW yet, so I can't comment, but the BM235 flashes the backlight in continuity mode - and it does so whether the backlight is off or had been turned on. (Yes, I have a BM235).
If the 121GW doesn't have this feature, I would like to see it implemented. The option to switch off the beeper is one I would be guarded about. That is a setting I would want to have automatically reset at switching off so the next time I turn the meter on, I don't interpret silence as a lack of continuity.