Every time you say "no" to deleting existing profile layers, a new copy of the entire EG profile (including the grid, labels etc.) is placed in the drawing and will cause your drawing file to bloat.
ACADuser
Civil 3D 2018, Raster Design 2018
Windows 7 Enterprise
Dell Precision 5810 Workstation
Intel Xeon E5-1630 v3 @ 3.70GHz
32GB RAM, NVIDIA Quadro K2200 4 GB GDDR5
DUAL 27" Dell UltraSharp U2713HM