The settings for opening the 3D search [3D Search] for the very first time are taken from the default template.

The The corresponding setting can be found in geomsearch.cfg > [ SEARCHTEMPLATES ] block > key DefaultTemplate. This template uses SizeDependent=0.

For example, if you want to activate the Include component size [Include Part Size] option by default, use the value SystemTemplate7. In this template, the SizeDependent key is set to 1.