thanks for the tips! I like the two layer option - light fleece with light jacket over it. I've been using my rain jacket for this, is there a big difference when using a wind jacket?
The biggest difference is that the wind jacket will be highly breathable (20 cfm plus) while the rain jacket will be clammy once active. Rain jacket does the job when sitting at camp. A wind jacket should be max 150 grams, and you can find cheap ones for <100 grams. The Patagonia Houdini and Arcteryx Squamish are on the heavier and pricier side. Another good one is the Kor Preshell by Mountain Hardwear. If you don't care about looks or long term durability, you can find some very light biking ones that are practically see through on sites like AliExpress.
Personally, I find this is the best solution for shoulder season hiking. Summer hiking the best solution is a sub 300 gram puffy when camping and no fleece. You shouldn't need an extra layer for hiking besides maybe starting with a rain jacket in the early mornings. It also depends how much you care about weight savings!