I’ve gained more experience with ceiling bounce test (thanks @2100), with results more consistent and repeatable. One of the bathrooms in my house, the one without windows so I could test all day (grin), was the test “chamber.” I did multiple measurements of High (highest of the brightness steps) and Turbo: 1 click to high, double click to Turbo immediately. Each time the battery was then recharged to full level and flashlight allowed to cool down.
Followed is the result of Samsung 40T vs Wurkkos battery in TS30S with SBT90.2, an extremely powerful & current hungry LED. Even given the “approximate” nature of a ceiling bounce test, the Samsung battery surprises me. Not just because the gain is so significant, but that equally high gain is seen in High mode. The difference is very obvious and as mentioned repeatable.
In Turbo mode, the gain of Samsung 40T over Wurkkos is around 15%.
In High mode, surprisingly the gain is equally significant, around 14%.
The test was repeated multiple times to confirm the incredible gain.
EDIT 11/9/2022: I finally got around to measure output with my Texas Ace Lumen Tube:
Stock Wurkkos Battery ~3980 lm
With AR lens ~4090 lm (~3% gain)
With AR Lens Samsung 40T+ ~4750 lm (3% + 16% gain) 
:+1: 
Second Wurkkos battery is better, measuring ~4160 lm stock. Samsung 40T’s gain over this battery is 11%.
The AR lens I used is UCLp Acrylic: UCL Lens - Flashlightlens.com - Online Store
Without doubt the Samsung 40T makes a big difference. The 4 Samsung batteries I tested got 4520 lm, 4730 lm, 4730 lm, and 4750 lm.
2 Wurkkos batteries:
