The Sofirn SP31 v2 LH351D. The same boat as the Convoy S2+, regulated driver (buck instead of linear IIRC so more efficient in the lower modes), no usb charging. Unknown how they compare in the high modes, as I have seen no tests for the SP31 LH351D version .
Wurkkos WK30. Larger (26650), more expensive (but no so much difference at Aliexpress), USB charging. UV( shame no filter) and red as a bonus. Unlike the FC11 no ramping, but the modes are regulated. Not sure which kind of driver is using. If the size is OK is looking like a good candidate.
Edit: the LH351D is 5000K, not 4000K.
New Sofirn SP35. A bit larger (21700) and more expensive. No LH351D. Ramping, regulated buck driver.
That said, not everybody needs regulation, or high efficiency at the lower modes. Efficiency is a concern if you are backpacking, cycling in the night for hours or you expect long blackouts, but for light urban use it’s not a concern. I don’t see regulation itself as a killer feature, except for long time activities where the efficiency aspect matters more (but more efficient drivers are regulated anyway).