f I initially leave some fields unmapped in a record type and later decide to map them, what happens to the data in Appian? What should be the best practice?
Let's suppose for instance that the system will need some unselected fields soon, but not yet
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If the fields are unmapped, then data for those fields is not synced into Appian. If you select more fields, then the data for those fields is synced upon saving the record type.
Do you have concerns about this behavior? Personally I would likely select all the fields that I expect to use (even if I'm not using them yet), just to make it one less thing I have to do later.