Currently indented text only indents from left, leaving the right magin sadly pressed across the page. To demonstrate:

Harry awoke more uncomfortable than he'd ever been in his life. The side of his face had been crammed against the steering wheel, his neck twisted at an incredibly painful angle. When he sat up, he found that one of his legs was tucked under his body and that he'd lost all sensation in it and he had to correct the right angle in his neck with a vicious snap.

Regardless, he felt more awake and alive than he could ever remember feeling. His mind, free of the stupor that had ensnared it in the last few weeks, felt quick and sharp. He fumbled for the door handle and fell out of the car, crashing to the moist, dewy grass below.​

The old DLP did this, and it functions better from a UI/UX/readability perspective.

A cursory examination reveals that adding indents produces this:

HTML:

<div style="padding-left: 30px">

Which, I mean, is terrible, but I presume when you initialize Redactor you can ask it to do padding-left and padding-right simultaneously in the JSON.