The signature field is used to sign the form, it applies to the form or collection of objects in the form. I don't think you can use it as a field in a repeatable section.
Yes. Everything I see says A signature field should not be repeatable and should not be inserted in a repeatable subform object. A form with repeatable signature fields is not valid and causes problems in Acrobat where the signature field may not appear at all.
The signature field is used to sign the form, it applies to the form or collection of objects in the form. I don't think you can use it as a field in a repeatable section.