small and rechargeable that holds its charge?

The Minix looks well made but 1) too complicated for non-flashaholics, the 2nd led tells you that already. 2) too easy to activate in your pocket. If it has a lockout mode to prevent this, that confirms the problem.

The only one of those rectangular lights that looks good to me for non-flashaholic users so far (keep in mind I haven’t used any of them irl though) is the Surefire Sidekick, which is somewhat larger than the Minix. It has just one led, not too many modes, larger battery, and its button is hard to activate accidentally.

Yes, the customer would have to read the manual.

I don’t own the Sidekick, but have read many negative reviews about the durability.

Keychain lights used by my family

Astrolux A01 - ok but strobe annoying. Lost one head as it uncrewed and took an Eneloop with it. AAA
Astrolux A02 - crap switch, gave it away AAA
Astrolux K2 - Rovyvon Copy, got one for each family member. Daughter broke the attachment point, all others aOK. UV, blue and red side light. Ramping main, good moonlight.No issues with charge retention so far, internal battery, 6 months old
Rovyvon A5U - Press and hold for turbo or double click for lower then medium high and strobe. K2 UI is better. No issues with charge retention so far, internal battery, 10 months old
Sofirn C01S - Nice light, good LED, surprisingly good output, twistie 2 settings 10 & 100 lumens iirc. AAA
Sofirn SC01 - Small, stainless steel body. 95 CRI SST20 4000K LED, twistie 2 settings 10 & 300 lumens, 10180 recharge in situ with micro-USB

TrustFire Minix in transit so can’t comment on that yet but big thumbs up for Astrolux K2 & Sofirn SC01 - I’ve got at least one of each spare NIB for when a gift is required at short notice.

minix would NOT activate accidentally, it takes too much pressure
imho

Another option
Trustfire mini 3,support both AAA and lithium (1 mode bright)