Sounds like you had some pretty unfortunate luck, but great to hear their contributions live-on. In any other quarter, you might have had 3 out of 5 solid candidates with the conditions and drive to continue.

Also it's pretty cool that you're attracting talent that is being scooped-up by the bitcoin industry. Don't be disheartened. Might want to generate some stickiness a few months into The Trial, to ensure that this isn't a recurring theme and that SN isn't just a springboard to finding more "cushty" stable work.

Be encouraged by the foundations you have laid, that it is now much more easy for people to jump-in and out to contribute and you're getting more eyes on the codebase at this point. I am sure the SN team want to see trialists turn full-on contributors & colleagues over time, but these new incentives will take their time to embed into everyone's way of working. And time preference will likely see to the rest.