Maybe making the 'extended interview' process more formal would be a good thing.

Formally have an internal 'contract' worker process where anyone they might want can be hired in to a trial pool, and projects can bring in the trial worker for small things quickly (maybe writing unit tests, or a fresh set of eyes, etc).

Every month review performance, make a decision to offer job as X, keep on for another month, or let go.

As a different part of this, alternating weekends might also be a more focused part of this, let someone that ALREADY has a job have a similar trial process on just some weekends, maybe with a more remote-work focus.