No, I'm not joking:
Now play Plinko with it!
that could be more annoying on a group ride than 'spoke a dokies'
Bianchis '87 Sport SX, '90 Proto (2), '91 Boarala 'cross, '93 Project 3, '88 Trofeo, '86 Volpe, '89 Axis, '79 Mixte SOLD, '99 Mega Pro XL Ti, '97 Ti Megatube, , '90 something Vento 603,
Others but still loved,; '80 RIGI, '80 Batavus Professional, '87 Cornelo, '86 Bertoni (sold), '09 Motobecane SS, '98 Hetchins M.O., '09 K2 Mainframe, '89 Trek 2000, '?? Jane Doe (still on the drawing board), '90ish Haro Escape
If you had only been running that a while back, maaaaaybeeeee, jus' maybe, that duffus who hit you with his car would have heard you coming and yielded to you your right-away!
Now can you make that work in backup mode?
I dare say a beeping Dynohub would be the perfect thing to infiltrate a roadie peloton with. Just tell them it is an audible cadence meter.
Backup mode? Sure, it'll work, but I don't know what circuitry is required to quiet it the other way 'round. This is AC, not DC.