It's a good idea that I've considered. However, I didn't anticipate the need for this when I originally designed Hashpass in 2014, and adding it now would be a breaking change.
I'm still considering it, but there would need to be a very slow, very careful rollout plan. Probably some transition period where users can opt into the new scheme, then eventually make the new scheme the default but still support the old scheme, and finally remove the old scheme to make things simple again.
Since this is a Chrome extension which collects no information from users, I have no way of contacting users about this. So I would need to wait long enough that users discover it themselves in the UI. All told, I'd guess it would take about a year for the full migration.
Yes, a checkbox is one way to allow users engage with this feature. There are other changes I'm considering as well (e.g., increasing the length of the generated passwords, avoiding characters that look like other characters such as 0 and O, etc.). You have the right idea, but the new experience needs to be designed holistically.
I'm still considering it, but there would need to be a very slow, very careful rollout plan. Probably some transition period where users can opt into the new scheme, then eventually make the new scheme the default but still support the old scheme, and finally remove the old scheme to make things simple again.
Since this is a Chrome extension which collects no information from users, I have no way of contacting users about this. So I would need to wait long enough that users discover it themselves in the UI. All told, I'd guess it would take about a year for the full migration.
Anyone is welcome to discuss things like this with me via GitHub issues: https://github.com/stepchowfun/hashpass