You can use Org Shape for this purpose. First, Enable Org Shape in the org you want to use as the source, set up the Permissions you need, then Create an Org Shape. Finally, specify the sourceOrg attribute in your Scratch Org Definition File.
Step 1: Enable Org Shape
As an admin, go to Setup > Org Shape > Enable. If your Dev Hub is different than the org you enable this in, enter the Org Id in the box.
Step 2: Permissions
Create Permission Sets with the following permissions:
To Manage Scratch Orgs Object Settings > Shape Representation > Create, Delete
To Use Org Shapes Object Settings > Shape Representation > Read, View All
Assign them to developers that need to create/delete/use Org Shapes, as appropriate.
Step 3: Create an Org Shape
sfdx force:org:shape:create -u <source org username/alias>
This creates the shape that you'll use in your Scratch Org Definition File.
Step 4: Use the Org Shape
In the configuration file, specify the org you want to use:
{
"orgName": "Acme",
"sourceOrg": "00DB1230400Ifx5"
}