It seems that they fixed the problem:
"FARKA F8 with high-efficiency new Engine DD2, constant current circuit (current regulated output modes): constant brightness in each mode, Non-Flickering in each mode, no noise. ultra-long burning time 100hours in ultra-low mode, max output OTF300lms.
LED:CREE XP-G 1B R5
Rated Input of LED Driver: DC3.0~6V
Use 18650*1 Li-ion rechargeable battery or CR123A*2
3-Stage Variable Output: High, Low, Ultra Low
Max Output: 300lms@1100mA(OTF,full high level)
Max Burning Time:100 hours@20mA(Ultra-Low level)
High(1100mA/OTF300lms), Low(350mA/OTF115lms), Ultra Low(20mA/OTF10lms)
Measured burning time:
High--2.5 hours, Low--8 hours; Ultra Low--100 hours;
Measured with*: single SANYO 2600mAH 18650 rechargeable Li-ion battery. Full recharged and continuous testing to get a burning time.
*The experience result will be a little different for the battery of different brand, condition etc.
With Low voltage cut-off protection
With Low voltage blink warning
With Built-in battery inverted-load protection"
I hope that the farka's D26 module could be purchase separately like they used to do.
An XP-G D26 module with neutral tint, low-med-high sequence, memory feature, no PWM will be great.