Well, for the 818, it's a near perfect light for my latest e-switch firmware for the ATTiny45 and 85 - I've been posting notes and updates here: https://budgetlightforum.com/t/-/34900.
Some noted features:
- easy mode up, mode down, single click ON to low or hi, single click OFF
- supports latest FET+1 custom drivers fully, with a low moonlight mod, optional
- simple access to strobe via a 1 second hold
- UI via side switch for choosing/saving 64 mode combos
- programmable lock-out feature
- selectable turbo timeout, up to 10 minutes or disabled
- can use a tail switch for mode switching w/memory as well
- Low Voltage Protection
It's easy to work with for a side switch light - lots of room, simple body mounted switch, plus a nice tail switch.