The original Lynx head was one piece but it was difficult to manufacture so they made a two-piece head.
Clearly the rotor head of the 105 doesn't flex but the blade attachments to it do (otherwise where does the flapping occur) so there are composite hinges instead of mechanical ones which I believe makes it a semi-rigid system even if the rotor head itself is solid.
I still can't see why sloping ground is more difficult in a 'rigid' system - you just have a quicker control response to cyclic and more control power.
Yes, you can generate rolling moments more quickly and you need to be very aware of bending stresses on the rotor mast if you use too much in-slope cyclic but it still isn't rocket science.
Perhaps the 105 head wasn't so critical on scratches because it wasn't designed to flex - the Lynx definitely was.