As I was trying to overcome this same issue without custom coding, I found a pretty simple workaround. When you build your form template in Design Studio or build a new form in your Marketing Activities, you will type the corresponding token into the 'Default Value' property of each field, like I have done here. Below, you will see that in the Default Value for my First Name field, I have typed in {{lead.First Name}}. I have done that for each field and as you can see on the left they populate into the form. Once your customer visits their PURL, it will do the same, but with the actual values of their record. The easiest way to do this without having to remember each token, is to have a practice landing page in your Marketing Activities and drag a Rich Text element onto your the art board, click the 'insert token' button in the Rich Text editor, find the correct token in the drop down and then copy and paste it into the 'Default Value' of your form.
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