>> I can't speak to Macs, but in Windows the configuration file is "dosbox-x.conf”;
On my MacBook Pro M4 running Tahoe 26.2 I see the following files that might be relevant.
Inside Xy4DBMac.app —
Contents/Resources/Files/appsettings.conf
Contents/Resources/Files/autoexec.config
Contents/Resources/Files/BDrive/ batch files