the four freedoms are the free movement of goods, services, capital and.... labor
That is palpably NOT true though Maf - and you know it. Freedom of movement is just that. The freedom to move wherever the EU citizen so wishes in the Union, in search of employment, or a place in that they wish. One could imagine that if a German moves to a hillside in Transylvania and becomes a leech on the goodwill of the poor people there, then his life would be made pretty unbearable - the locals would physically remind him of his freedom of movement right there and then - but technically - he could move there is he so wished. The whole meaning of the four freedoms are in the word right there.
So called three month contracts or skills tested visas are not within the scope of freedom of movement.
FOM worked pretty well up to now. Of course, xenophobes grasp at straws, because they don't do "different". As a case study, let's take a look at transport. If a British lorry driver has problems making a living because of competition from some Polish chap, then that's a difficult one, but just sometimes it's his own fault.
When I need to make more money I teach English on a Sunday. When I can't be arsed, I don't. The money I then don't earn is down to me. I am free to do as I wish. The 99.99 other percent recurring of the population of the EU should also be free to make their own decision in such matters. If a British lorry driver (my brothers' neighbour in Leicestershire) is too lazy to travel to where the pick up is on a Sunday then that's his problem - and somebody else will volunteer to accept that load - nowt do with freedom of movement, simple supply and demand. Of course the British guy demands his "rights" and kicks up a fuss - because he forgets the EU benefits that he is free to drive his rig throughout Europe with little paperwork and with no added charges. He wasn't even born in 1973 and doesn't understand the difference in living standards BEU - almost as archaic as life BC.
No 4 freedoms = a bygone world, which doesn't seem to affect David and Sam as they jet around looking for the next photo op, or JRM, but the rest of us have less opportunity, even the lazy lorry driver - who his village pseudo thatched roof cottage and 4 cars in the drive, doesn't need to work on a Sunday, and doesn't want to - but begrudges the Polish chap in the next village the gig because "these foreigners are taking our ******* jobs".
(As spittled in my face at said brothers' local pub a few years ago by said overweight British haulier)