I really like this design, however I think it has a problem:
According to the datasheet the TPS610986DSET has no feature to disconnect the load at low battery voltages. I think the result will be that e.g. a ESP32 or other power hungry chips will not power up properly. The TPS63031 might therefore be a better fit.
btw.: Do you still sell assembled versions of this design? Would you be willing to create a new version with the TPS63031 and probably also with 10 or 20F capacitors or an board to solder your own capacitors.