I have one where I have all html elements turned on for when I need them.

I use them mostly for coding. I also have another that is essentially just my normal profile without the table verbosity for when I get tired of listen ing to that info. I should probably use more, but most of the controls for changes are convenient and thus I never seem to get around to it.

I have one that reads navigation information in documents and spreadsheets. I have one that is set to use a louder voice when I'm using Spotify. I have one that I rarely use these days, which is set to notify me of the time using the Clock add-on, at more regular intervals when reading books.

Mine arn't manual but I do have triggered ones for specific games. Prime example: I use a different synthisizer when I'm playing something like Diablo IV. There's a lot of sounds and music happening in the game that sometimes happen all at once, so I have different speech settings set up so that my synthisizer changes to something I can hear clearly over the in-game action.

I use them for changing voices.

I use nvda+/ to toggle my "Demo" profile, for screen recordings or live demos. It switches to Microsoft Eva, turns down punctuation, turns off a lot of document formatting announcements (most of my demos are for sighted people who might not even know what a landmark is), turns on the visual indicators, turns off screen curtain, turns on word echo, etc. This would be an absolutely ridiculous amount of work without the help of configuration profiles. Still wish #17415 wasn't such a mess.

I use a configuration profile for something very silly. Sometimes I don't want the braille display to scroll while I'm reading with say all, because of the sounds it makes. So I have a profile which avoids it.