I think this is the same driver HKJ has tested here
It’s only 1xAA.
800mA with 1.5V perhaps, but not with a single AA/AAA. Extrapolate the light blue line (current in) to 1.5V and you would need about 3.5A input current without voltage sag to get an output current of 800mA…
With a bench power supply it might work.
As far as I remember I checked all of HKJs driver tests when looking for a good boost driver. The drivers based on the PAM2803 (nanjg110 and our Fasttech-driver, HKJ tested both) had a better efficiency than this one and were only topped by the LD30 which is much more complex. But I did this long before this thread started when I hadn’t hoped to get a driver with good modes.
If you want to compare drivers you can find a remarkably long list of tested drivers on HKJs website
www.lygte-info.dk/info/indexLedDrivers%20UK.html