Hi Dave, this is a nice question and the answer is YES.

The PCB’s have been designed with a connector where you can add a clicker. See it in the picture attached.
I recommend the self oscillating 3V piezo buzzers. Here’s an examples:
http://www.ebay.com/itm/Black-3V-Electromagnetic-Type-Piezo-Buzzer-Continuous-Sound-Pack-of-20-/271455683312?hash=item3f340502f0:g:b9wAAOSwu4BVyxYp
You will also need a firmware upgrade, as by default the digital output pulses on that connector are disabled.

Radu

hi Rob, are you asking for a way to modify an existing unit or is this a question/suggestion for a future hardware revision?

Thanks,

Nothing fancy there, really, these were some 3.3V (5V is good too) active buzzers . They are controlled with a NPN transistor so you can use pretty much anything. You can also connect a LED instead. Here is another link: https://www.aliexpress.com/item/33059794164.html and a picture attached.