Answering my question (partially). Found a great Mac-only app called "Velja" which does exactly what I wanted. It allows you to define rules based on URL patterns and "routes" to the appropriate browser window.
Now I just need the same thing for Linux.
The easiest thing to do is to probably just drag the hyperlink into the right window manually.
Or maybe you can script it at the OS shortcut level, making a URL handler script that captures all https links and then does a regex on them to decide which Chrome profile to launch. Note that the Chrome command-line to open a specific profile seems to change every so often, so not sure which of these is current, but hopefully one of them still works... https://superuser.com/questions/377186/how-do-i-start-chrome...