I got this idea just yesterday and I would like to know if anyone has tried it. I am thinking of a modular UQ with two layers, basically two UQs which would attach to each other with zippers on the long seams. Inner layer would be stuffed with Primaloft and the outer with down.

I know this isn't ideal if you want to go (s)ul because you would basically use around 50% more fabric for the UQ. The catch is that in the summer we usually have temps around +20-30C (68-86F), averaging at 25C (77F) and in the winter -20-30C (-4-22F) (it can go down to -35-40 depending on the location + wind there is still the wind effect). So there can be over 60C changes in the temperature during the year. You could probably use the down UQ in the spring/autumn, the synthetic in the summer and synthetic+down in the winter. You could also just use down in both layers, I am just curious how well Primaloft and down would work together.