That's not a tradeoff I'm comfortable with, "even" in pre-release software.

I'm not accusing you of this, but in other cases I've seen proponents of something say "This isn't a big deal, it's just starting out". Then, when people continue to complain a year from now, the defenders say "This isn't a big deal, it's always done this."

Vivaldi looks interesting, but I'd wager that there's a decent overlap between the Power Users they're after, and the group that values their privacy the most.

Privacy has nothing to do with it. If the software is not yet ready, users are expected to encounter serious bugs. Your QA department is paid to help provide you with information to diagnose and troubleshoot those bugs, but users aren't, so you need to collect that automatically.

If they explicitly say they will stop in the release version, I would accept that argument. If not...

> It's perfectly reasonable to expect extra data to be collected when using prerelease versions of software.

This is incorrect in the world I live in, and I do not want to visit a world where it is correct.

You're in the wrong world then, buddy. If the software is not yet ready, users are expected to encounter serious bugs. Your QA department is paid to help provide you with information to diagnose and troubleshoot those bugs, but users aren't, so you need to collect that automatically.