my k1 max is now perfected to run at 600mm/s and 1000 moving speed. shakes quite a bit when runs at that speed, but output is consistent.
nozzles now allow 48mm3/s. took some effort to make it work, but, it runs. and runs all klipper, full remote access, standard moonrake, love it.
frame would benefit from more rigidity, or course, i keep thinking of taking it apart but too lazy as it still does 95% of anything i want. the only big upgrade i did was install of the second cooling fan assembly on the opposite side from the stock fan, to mimic voron setup, and it made major difference in cooling.