I've submitted v1.2.0 of this plugin to provide support for Zen Cart v1.5.2 and later. Turns out that these versions of Zen Cart, while incorporating the trace-related processing in the base distribution, are not going to provide the configuration switch to enable/disable the feature ... that's what the update's for!

If you are already a user of this plugin, you don't need this update but you do need to remember to delete this plugin's /includes/auto_loaders/overrides/config.core.php and /includes/classes/class.base_trace.php files as part of your upgrade process.