Actually, it is not difficult to keep a constant oven temperature. This stove was designed for cooking so keeps heat in the cooking oven rather well for "normal baking times". That is, it will not be *exactly* 400°F for 30 minutes, but close enough to cook, properly, within 30 minutes-ish. One must pay a bit more attention of course. But that is part of the fun, being more "hands on" and not so mindless.
For example, you can see from the video I posted above, at min 5:05 the internal temp is about 220°C (this is an Italian Stove so temps are in Celsius, but that is about 430°F). And 40 minutes later, at min 5:30 (hard to see the temp gauge), but the oven is still at about 220°C.
Yes, there is a bit of learning curve for sure to keep consistent heat longer. I can, with firebox and air flow manipulation, keep a really consistent heat in the oven for hours. But it takes practice.
As for dutch ovens, I have never tried them. But a friend of mine swears by them as ideal for cooking. So definitely an option (but also, of course, has a learning curve).