Not a happy report here on our experience; Apple was good...but the hardware.....?
I took my wife's 2018 MB Air to the Apple Store after she had been complaining of extra spaces happening randomly. They tested it in the store and found there to be a problem. They blew air into the keyboard and said if that didn't work, we'd need to send it back to Apple for repair. I took it home to my wife; it was no better. I called and they sent us a box to send it back under Apple Care. This was August 2019. They did major work on the laptop, replacing the top case (which contains the keyboard), the motherboard, even the screen. It is now October 2019...and the keyboard is adding extra spaces again.
We could do this time and again but, it seems to me, that the issue is the butterfly design. My wife now hates her laptop. And because it is Mac, and because all Apple laptops have this keyboard, there is no alternative for her. I will try the above suggestion of turning off automatic period when double-stroking the space bar. But this is a bad situation for long-time Mac customers.