So don't talk to them, then they can't "push" you! Also to note that if you are in VMC outside CAS there is nothing to stop you flying IFR which then makes FL100 available!
Haha! So true... But unfortunately I'd rather speak to someone. I am rather impartial to the altitude / flight levels unless there is considerable tailwind / headwind components to take into account. With regards to IFR vs VFR, I don't have an IR yet, I am working on the ground school which is extensive - I only hold the IR(r) which in Europe does not allow me to fly IFR.
Whereabouts in France were you, where there was uncontrolled airspace at FL100?
I was here:
Just south of Cherbourg's zone flying towards Rennes Saint Jacques. It is mostly uncontrolled until you reach Rennes' zone. Their clearance through the zone was quite literally "OK cleared, report overhead" which I thought was brilliant!
I think we may perhaps have gone on a tangent to the original question though? ;-)