Here is a suggestion what you could do to support PETG only adjustment:
NOTE: I am yet to test the +0.02… I tried -0.02 and that was still too deep. As cool as the Bambu X1C is it is not well tuned for PETG printing out of the box… and even babies can print with PLA just fine… so it is up to us… tuning it in ALSO means retraction, wipe and z lift when travel settings… unfortunately not all of those things are included in the Bambu slicer but I am currently tuning in an excellent filament to match the performance of my Prusa, which can print with any PETG any day perfectly, no failed prints… I am confident I can get there with the Bambu too.
;===== for Textured PEI Plate , lower the nozzle as the nozzle was touching topmost of the texture when homing ==
;curr_bed_type={curr_bed_type}
{if curr_bed_type=="Textured PEI Plate"}
{if filament_type[initial_tool]=="PETG"}
G29.1 Z{0.02} ; for Textured PEI Plate with PETG
{else}
G29.1 Z{-0.04} ; for Textured PEI Plate
{endif}
{endif}