@JustPete, I think the thread was this one.
@scruffynerf, don’t you mean 4 inch? Mine measure 10 to 12cm between bulbs, depending on whether you measure between the casing or the LEDs themselves, and I haven’t seen any other spacing from the usual sources (Banggood, AliExpress, Alibaba, etc). I suspect that the voltage drop for 5V and thin wires might be a limiting factor.