There are a lot of technical and translation errors and lots of omissions in your link from Digikey from Pimoroni from WorldSemi Ltd. Perhaps it's intentional to confuse competitors. Their specs are so bad in some areas and great in others, that tells me heat is a problem for rookies and there are lots of tradeoffs with good and bad designs for substrate thermal control.
I don't have to test one to know you can damage it with 12V with an estimated 40mA or so total LED current the chip will soften or melt the epoxy and damage the wirebond with almost 0.5W in a chip with no thermal, power or current specs in the datasheet. (They must make more profit on their stripleds than the LEDs.) That makes me wonder how Pimoroni are related in the UK. (just another OEM user)
The other part datasheets are correct and some improvements on current control but no LEDs. The WS2811 operates from 5 to 12V. But as usual with World-Semi, the datasheets are horrible, but getting better slowly. The 12V refers to the external LED Anode string, not the IC power. Somehow this info was put into this datasheet by mistake because the LED's are internal and Vcc is 5.3V max..
But they have excellent solder and humidity drying advice that if you don't heed, may result in popcorn failures during soldering, since optical clear plastic is soft when hot and so hygroscopic with a lower glass transition temperature. The moisture pressure can pop, and shear gold wire bonds internally. So read carefully. If humidity is above 30% solder within 1 hr of opening a sealed bag. Maybe longer if lower.
I highly recommend you add an SCR to crowbar the power if detected above 5.3V to let the 12V user try again with 5V. They work best with 3.5V needing only 0.1V margin for the FET current limiter and <=50 mV current sense resistor. But it's hard to prevent voltage drop at the end of a 5m string , let alone two of them in series which is problematic on some cheap thin traces on FPC.
The good thing about this part is they suggest no caps are needed, which are shown on other similar parts. The bad thing is you probably need caps and they forgot to tell you when or why they are needed.
Here they incorrectly say "Also include a precision internal oscillator and a 12V voltage programmable constant curre-nt control part, effectively ensuring the pixel point light color height consistent"
They must be referring to their 6 pin parts with separate Vcc and Vdd yet even those specs say the same thing but have the same 5.3V Vmax for both. I guess they don't have all the bugs out yet to average the 2kHz PWM and control the current with a high R small C pF internal cap to average the current and keep it regulated within 3% like on the newer parts.