Currently, different field types will display instructions in different places. For example, I have a View that includes a Number field and a Paragraph Text field. I've specified instructions for both fields. The Number field shows the instructions beneath the field, while the Paragraph Text field shows the instructions above.
This is a problem for two reasons:
1. It looks like a mistake, which in turn makes my business look less professional to my customers
2. It adds to the cognitive load for users reading and understanding the form when the field label, field, and field instructions are not in a consistent order<
I think the instructions are best placed beneath the field label and before the field, since users reading down the form will then see the label and the instructions prior to entering data in the field.