Double posting this here as well: https://budgetlightforum.com/t/-/25032
I did the tests. First removed the diode, bridged the pad with solder, and saw absolutely no difference in the parasitic drain at all - zero, nothing. Still doing in the 0.30 to 0.32 mA range.
Then I pulled the 22K resistor. The light acted kind of weird, because I didn't re-burn the MCU with firmware not supporting LVP. Anyway, it would settle down, and go into its sleep state. There I measured in the 0.16 mA range, which is about exactly what I expected - it went to half the draw, as calculated from the resistor values.
So, not sure why the diode had no effect or did I mis-understand if it was supposed to help?
Btw, in terms of draw over time, a 0.16 mA steady draw would drain a cell 1 Ah in 260 days, if I did the math correct.