Just like it says. Getting the correct number of LED’s in a strip is tricky at best. I’ve even had the manufacturer tell me the wrong numbers. (Found this out after I took the device apart) Is there a way to add a tool that does this automatically? That would make setting things up quite a bit easier for the end user.
Unfortunately not, there’d need to be something telling the tool how many LEDs are on the chain. LEDs themselves don’t output any information. 
Hmm. Each LED is a data point, right? So we’d need to count the data points instead of the LEDs maybe? Or, maybe it could sense it using the voltage drop to determine the number? Just spit-balling here.