If you want to enhance or modify the integration or field mapping then you need to develop an extension (app). In order to get/see the enhanced mappings, you have to click on the "Use Default Synchronisation Setup". This function deletes all mappings and adds then all mappings from all extensions. This might be OK for the very first deployment but in an existing environment where default settings have been changed, match coupling rules have been setup etc. it will wash away all these settings and can cause synchronisation chaos.

It would be great to keep all existing settings when adding a new version of an extension enhancing the integration even further.

One approach could be to have a snapshot the current settings, refresh all mappings as currently done, and then re-applying changes from the snapshot. Some will not be possible if for example an integration was removed in the extension etc. This could be shown with a conflict list so that the user is aware of what wasn't been able to apply.