I have to disagree about the group being faulty the grab point on my LR is at the horizontal or lower. This is all down to preinfusion pressure, my LR with the pressure transducer will bite at 45 degrees if the preinfusion is set to 1.2 bar, if the preinfusion pressure is set to 3 bar the grab point is horizontal , so no fault at all with the design or permanent of this group. I have found a difference in using the genuine londinium seals and the cafe last seals. The genuine seals suffer far less from the slippage (which is a real thing) but neither suffer if the group is greased correctly.
also if you grind finer (as most londinium owners do) and allow for complete saturation of the puck during preinfusion you will not have the high grab point.
distribution is fundamental as well, as if there is any channelling at all then complete saturation at preinfusion is not possible and this will affect the grab point.
my advice, go back to basics, regrease the group and seals (which ever ones you are using), ensure drips from puck prior to raising the lever and make sure it is an even extraction across all of the base of the basket.