I am requesting that field customizations and configurations (such as default values, domain import from CSV) are available in the Data tab of the AGOL hosted layer, just as it is available in Field Maps Designer. The reason for this is when I need to make schema changes or updates to the data, I typically have to have multiple windows open and various places within the ArcGIS environment I am making changes. It does not allow for a time efficient or streamlined process in GIS administration of layers.
Field Maps Designer allows for setting default values, templates, etc. and domain imports from CSV. This should be available on the layer Data tab as well. Not sure if this idea has been submitted before but happy to give it a kudos if it has!
