I doubt it can be used as the main output of the interface, though. And how are you going to control volume in this case? Consider connecting the monitors via analog if you have no budget for a DSP-enabled interface that can control volume on its digital output. And this Topping is not the best choice IMO due to the analog pot-based volume control that will introduce artifacts and channel imbalance; at this price range I think a MOTU M-series interface, a 4th Gen Focusrite Scarlett, or an Audient one, either their iD series or the Evo series (they control volume digitally), would be a much better choice.
Let's not deceive ourselves: in this case, it's about price, not about quality
If this is the case, you are correct.