The Thrunite T2 is a 1x21700 flooder with the highest efficiency I've ever tested in a flashlight. It features USB-C charging, and can be put in a pants pocket in a pinch.

The Nitecore MH10 v2 is a general-use flashlight powered by a 21700 Li-ion rechargeable battery, with onboard USB charging, and the ability to use a great many different sizes of Li-ion cells.

The Xtar ST2 is a USB-C PD fast charger for larger cylindrical Li-ion cells. It can charge two cells at up to 4A and has indidivual temperature sensors to prevent overheating. Its performance is impressive, but mine proved unreliable.

Acebeam says the L30 is "like a side-arm that takes shotgun shells". That's been done and isn't a great idea, but the L30 is. The high-only tailswitch with all other functions on the side switch is what I would consider an optimal UI for a duty type light. Output is around 4000 lumens until heat limits it to 2000.