after working through 'beforePrintStarted' script routines cura issues a
G0 F6000 X.. Y.. Z0..
if X and Y coordinates are small the high feed rate maxes out the Z rate and plunge
the print head in a quite 'unseemly' acceleration and speed toward the build plate,
former versions of cura issued F3600 which behaved more moderate
to avoid rapid Z axis movement on first positioning I cured the questionable sequence with cura's post processing module
cura/menu/extensions/post processing/modify g-code - search and replace
search: (F6000)( X.+Y.+Z0.+)
replace: F3000\2
regExp: yes
replaces
F6000 X.. Y.. Z0..
with
F3000 X.. Y.. Z0..
there should be only one line with F6000 with Z0.. coordinate, so check your 'beforePrintStarted' script
regExp explanation
group 1 = F6000 -> F3000
group 2 = X.. Y.. Z0.. -> \2
(printer Creality CR-10S, cura 4.3)