I second the Rapha classic vest. Two rear pockets and a little stretch due to the rear center mesh vent. Very light and easy to pack. I also have this vest from POC in chartreuse. Two slits in the rear that allow access to jersey pockets and it’s a bit warmer and tighter fitting than the Rapha. Both pieces breath very well. The zipped rear pocket is nice and being black, hides the inevitable splash marks. YMMV of course.
https://www.jensonusa.com/Poc-Resist...o-XC-Wind-Vest