Got my board today, very pleased with it. Measures 25.9uA in deep sleep, a good result.
Observations - to the uninitiated, it could be difficult to figure out how to power it in low power / sleep conditions, I mean not via the USB port, I think you could usefully add some examples, or documentation that sets that out - how to... etc using Vin and Gnd.
It would have been a perfect board if it had an on-board e.g. TP4056 battery charger and a battery connector JST style and finally on IO35 a voltage divider to measure Vbat using two 470K resistors as a voltage divider, that would add ~5uA to sleep current which is negligible. There is space for all of that. I like the fact that you've included two 3.3v/Gnd connectors too.
All the same, very please with my purchase.