Hi Micro Covid team!
First of all - let me say that I think Micro Covid is amazing and your work is fantastic!
I helped build a similar tool https://shouldigooutnow.com/, which is a little bit simpler than Micro Covid. We built it over the last couple of weeks without any knowledge that Micro Covid existed. So, reading your whitepaper and looking at the code has been really interesting. You might find it interesting to read about our methodology - we've done a few things differently.
Our code is open source, here is our core risk model, we've tried to keep it as short and clear as possible.