I always run short weekend, mainly to avoid having to do thes one-dimensional upgrades over and over again. When you get an offer of 5% increase in rear downforce for the 4th time in a season I do think whats the sodding point?
But anyway. The point I was going to make is in the Virgin last night I was playing and got offered 'reduce rear tyre drag 5%' which apart from the shock of something new, I completed. Once doing the objective and completing a setup I was happy with I quit the session, as I always do. I quallyed as normal and at the start of the race the engineer told me ''we've made some changes to the rear bodywork, you should notice a bit less trye drag now'
So im not sure you do have to complete the session to get it to count.