So my idea is a slightly larger system and the flexible circuit is just a central part. Basically change the ease with which wearable LED garments are fabbed. There are RGB LEDs on the market today that are a digital three wire system with a constant current driver internal to the LED. So make some standard tape widths (2",4", 6" etc) with groupings of three traces running the length (10m or longer) basically as many trace groups as can fit easily. Here is where the improvements start.
Create a online tool to order custom patterns of the tape. Example: 1 LED every 4"; offset 2" every row.
Now use something akin to a CNC Vinyl cutter to split the signal traces under each LED before placing, and add perforations for increased flex depending on the users specs. Also cut holes (¼") say every 1" to increase breathability.
Now pic-n-place (or hand place) the LEDs based on the custom order.
Use the Vinyl cutter to custom cut a top sheet out of a thin material or just vinyl based on the LED placement.
Laminate these 2 layers with a third cotton or nylon backing cloth.
The perforations should allow for added flex where you want it, the cover sheet and backing fabric add sturdiness, easy integration into garments and protection to the circuit. If the proper materials and adhesives are specced this could be a washable durable way to incorporate addressable LED’s into garments.