Last pool hose I tried turned onto a train whistle, like maybe even a tsunami siren. I could not turn off the vac fast enough.
On the LR3 Still is okay. It gets hard mounted at the dust shoe, and hard mounted at the top bearings. That gets squished into the back hooks. Even a stiff hose should not really put any forces on the cutter. I also think it relaxes after a bit of use.
Top mount is okay, you just need to be really careful not to add any forces as the machine travels to the extremes.