How to use E-signatures in the form?

Assuming an organization would need additional licensing in order to incorporate an e signature for a form? For example, would we need JotForm and Adobe Sign licensing? Or JotForm and Sigplus in order to complete a form that requires a digital signature?

You may use the signature feature in JotForm even with the free plan.

You may use our native signature widget or use the adobe or docusign widgets.

Guide:https://www.jotform.com/help/433-How-to-Add-an-E-Signature-to-Your-Form

Please check it out and let us know if you have further questions.

Are there caps on how many signatures can be collected even using the Adobe Sign widget or others? Are those limits set by their subscription agreements?

If you're using Adobe Sign, their own limit applies. Here's their limit per account https://helpx.adobe.com/sign/using/transaction-limits.html

If you're using our own Signature Widgets (E-Signature & Smooth Signature), there's no limit when collecting signatures. The limit goes with submissions. Check out pricing page to know more about the submissions limit per plan https://www.jotform.com/pricing/