Whenever you are using Signature Field in your forms, and are willing to use that field in your generated PDF and Dynamic Email, it is always recommended to use the SVG converter method. With the DOMPDF converter, it is not possible to choose the size of the signature, so you would see it as very small.
Using Signature Directly in the Email is not recommended, because all email softwares don't support data URI and it may result in the below output.
As such, it is recommended to use our Dynamic Email action for the email.
Also, you can't use the signature field in a dynamic email message to get the signature in your Email.
As such, it is recommended to use PDF Generator Action alongside and use the form tokens in the Dynamic Email Message field to retrieve the PDF.
For creating the SVG file, it is recommended to use Inkscape which is absolutely free software.