Hello, thanks for the question! Custom fields loading into Pigment is supported for Jobs and Offers data from Greenhouse. However loading custom fields from Openings is not supported at the moment.
The issue you are facing may be because “Target Start Date” was added as a custom field in the Openings object, not the Jobs object. Hence the field will not be imported. As this issue may be specific to your account configuration, please work with your Solution Architect / CSM or contact our Support team to investigate further.
Thank you!