I thought the diktat required us to either test at one of the official centres or at the actual venue we are visiting. The official tests are presumably documented, but we have to show ID first, so they can forget that!
In practice, so far, none of the restaurants are requiring a test, so I can't comment on their procedures.
If I fail a COVID test, there is zero chance of me voluntarily going anywhere near a doctor, unless I were seriously ill. Which could happen, but is very low probability.
The plan would be to isolate in my room.