the number of folks who will run bespoke solutions will be so small that it’ll be insignificant

For the vast majority of people, you are right. But for the very few malignant actors, that is the thing they’ll do. It will make ASIO’s job harder as they’re now trying to trace foreign VPN’s, custom-made encryption programs and other stuff that I personally don’t know about (I’m not overly knowledgeable about such computer things).

The >99% of Signal users forced into the sunlight aren’t the threat. It’s the <1% of Signal users who ‘go underground’ that are the threat.