If you’re looking for a way to conflict test your store without letting your customers know, you can try Check Conflicts.

While the plugin and theme activations are not reflected to your site visitors, anything else you save to the database will be recorded. Only use this plugin to test activating and changing plugins and themes, and not to make changes to any other data unless you know what you’re doing.

Usage:

• Install and activate the plugin.
• Install MU plugins required by the Check Conflicts plugin via WP Admin > Check Conflicts:
  
• You can select the theme you want to activate, and the plugins that should be active for your IP now:
  You can select multiple plugins by using ctrl button on windows, and cmd button on mac. You’d want to press and hold the buttons, while selecting the plugins you want active using your mouse/trackpad.
• To reset the changes, you can click the Reset Settings button (this will only be clickable if you’ve saved settings previously)
• To uninstall the plugin, please reset the settings first, remove the MU plugin and then deactivate and uninstall this plugin from the site

Example Scenarios:

Conflict testing WooCommerce core?

1. Switch to a stock theme like Storefront, only selct WooCommerce under Plugins – Save Settings
2. Try enabling the original theme and then check if you can replicate the behavior
3. If not, try activating the other plugins one by one to narrow down the conflicting plugin
4. Once you’ve narrowed down the conflicting plugin/theme, reset settings and reach out to the relavent support team with your findings.

Conflict testing some WooCommerce extension? (Say WooCommerce Subscriptions)

1. Switch to a stock theme like Storefront, only selct WooCommerce and WooCommerce Subscriptions under Plugins – Save Settings
2. Follow steps 2 and later from above scenario

If you have questions specific to the plugin itself, please post them in the plugin support forums: Support » Plugin: Check Conflicts.