You can add @url to the end of the field reference to just get it as text so you can format your own link so for my requirements with the stripe netsuite connector where I want to use the html field with my own text in it I use

<a href="${record.custbody_stripe_payment_link@url}">Pay Now</a>

and your one would be something like this

<#if result.custitem_dp_image1?length != 0><img src="${result.custitem_dp_image1@url}" style="width: 100px; height: 100px;" /> </#if>

Sometimes you just have to wait a few years for the answer.