I have only spoken to them via messages on their FB page. The guy that I "spoke" to confirmed that they don't have a separate "drop back" indication, so they should all stay illuminated for the same amount of time (around 10 seconds), although there can be slight differences due to the components used.
Like I say, I'm not bothered too much, certainly not enough to start sending them back at this stage, and it only seems to be the one that is doing it.
Other than this small hiccup, I'm really pleased with them, although I've only used them a couple of times. Using them with the slimlites give a great indication of what's going on at the business end. It was a little windy on Tuesday so I used the duocarb arms to hold the bobbins in place, and they too work well.
Obviously not used them in the rain yet.... so only time will tell lol!!