As a cyclist who once got that stuff in his face: yes, please look first. Expecting others to make a noise just in case they might get a bioweapon dumped on them is not nice.

Wait - are snot rockets a common thing for cyclists?!

…and they can get that much distance on their rockets?

Not usually. This Prius was practically in my armpit.

Absolutely, I was in the wrong. But if you're entering somebody's bubble, an "on your left" is also courteous.

I think the idea of EV making additional noise is flawed. The important thing is that people should be looking when using roads and not just relying on hearing. Deaf people are allowed to drive and they can certainly cycle safely as well as long as they just look around a bit more to keep aware of what's around them.

Having fake noise just encourages pedestrians to keep looking at their phones and not use their eyes when crossing roads or cycle lanes and they can injure themselves or others by doing that.

Also, there's far too much noise in busy areas as it is, so it seems unhelpful to deliberately add extra noise to the environment.

The main danger in my experience is that it is harder to hear if the EV is operational when standing still.

If an EV is standing still, then I'd rate the danger level to be zero.