The important thing isn't whether you can switch projects, it's knowing which way your mind and muse work in the present circumstances. If multiple projects aren't your thing, then just ignore the new stuff, or make a few notes and move on with your main project.

One thing I've found over the years is that often these shiny new ideas aren't nearly as good as they seem when they flash their enticing little sparklies in my brain. I go after them, find nothing there, and then have trouble getting back to my original project. Sometimes when I make notes, when I go back, the idea is flat and dead. I used to think, "Oh, no, I killed it by ignoring it!" But more and more I suspect that they weren't strong enough to live in the first place.

Experiment with it if you want, but if that's not the way your mind works, you aren't likely to get much from it. And it seems like a bad time to be experimenting.