You could enclose the long content inside a div and give it a fix height, so users would only have to scroll down to read the content but the agree/disagree buttons will always be visible without scrolling.
You could do this by editing the specific terms popup that you know have long content:
Dashboard > Terms Popups > Edit
In the editor, instead of “Visual”, switch to “Text”, and enclose the whole content with a div, like so:
<div class="termscontentcontainer">
Your long content here.
</div>
And then in your theme’s stylesheet, give it a fix height with overflow auto, like so:
.termscontentcontainer {
display: block;
width: 100%;
height: 200px; /*change as you like*/
overflow: auto;
}
Going forward, I think I will probably incorporate this in the plugin’s next update, to give the popup a cleaner look.