No you won’t hurt anything. 3.75” is pretty standard. Many aftermarket wheels have that backspacing.
With that said, it’s not ideal. Your scrub radius will be much higher which will negatively affect your power steering at low speeds and will put more stress on your wheel bearings. You might also find the tire rubs the inner fender liner and/or control arms at full steering cut. Or you might not. The backspacing can help by getting the tire away from the control arm, but the scrub radius hurts because the tire moves fore/aft in the wheel well as you turn.
It will be fine. I think 30x9.5 tires on a 2” lift is a cool look for XJ’s. I would probably prefer a 4.5” backspace, but it’s a pretty small difference and there are less options.