Hi Brian,
Welcome to CPF.
Wowtac lied about A1s output. It was never 1100Lm, more like 875Lm for a few seconds and dropping off rapidly to below 850Lm within 4 minutes or so and then drops suddenly to about 475Lm, and continues to drop from there across its runtime, all the while with PWM.
Since no one has mentioned yet, I'll recommend the
Zebralight SC64c LE 18650 4000K High CRI, which is 90+ CRI, regulated for constant brightness, is incredibly rugged with potted electronics, strictly speaking doesn't use PWM, and max brightness starts at 828Lm, which drops with voltage to around 800Lm before step-down around 3 minutes to about 490Lm, which it will maintain for nearly 3 hours. After step-down the user can continue put the light back up to max brightness for ~3 minutes at a time by double pressing the button. All other modes maintain steady constant brightness without step-down while capacity remains. Nearing the end of capacity, it will step down to 15Lm and, though the graph below ends the test a few minutes after final step-down, a Zebralight will continue to run for many hours at a low mode, continuing to step down to sublumen levels when necessary, and not leave you in the dark until your cell is entirely depleted. All Zebralight models are programmable, so you can choose the brightness of your high, medium, low, and submodes, or whatever mode single or double press starts.
If you want something brighter with 80+ CRI, consider the
SC600w Mk IV Plus 18650 XHP50.2 Neutral White. 4500K, 2300Lm. Graphs below show brightness and runtimes for levels 12, 11, and 10, respectively, with better than 1800Lm for 20 minutes, a rock-steady 1280Lm for nearly an hour, and a rock-steady 700Lm for just over 2 hours. It's slightly beefier than the SC64c, but smaller than it looks in the product page images.
Here is a video review that shows its compact size.