You've already done the right thing by booking the trip in F, rather than (as some do) booking in Y and naively expecting to get upgraded.

I don't suppose it will do too much harm to mention it to the CSD or have a note put in the booking by some ruse or other. The only danger I can see is that people might then assume you're there because you got an op-up. When I was flying once with a broken foot, a couple of BA staff (although not cabin crew) clearly assumed that BA had moved me to accommodate my foot, whereas I had in fact paid for the ticket long before the foot misbehaved.