The output impedance of most guitar pedals tends to be extremely low. Maybe not quite as low as a line out, but compared to the relatively huge input impedance, the difference is negligible. Nobody ever suggested putting reamp box between two pedals did they? But it’s the same kind of impedance “mismatch”, so why not?!? Because as long as the source is low enough compared to the load, everything is cool. The source just can’t be too low. Lower is in fact better from the standpoint of passing more signal in both amplitude and frequency range.
Unless it’s something like a fuzz face, the pedal doesn’t care at all about the impedance of the source. If it IS a fuzz face then it really probably shouldn’t be in a ”reamp” situation to begin with, but would need a rather large inductor in series to react more like you’d expect. In fact, an actual pickup is about the best thing for it, but it will of course add all the noise you’d expect.
Now going back in is maybe a different story. Pedal outputs do tend to be bigger, and some with really high outZ can start to look too big for some of the lowest Z line ins. Most pedals into most line inputs work perfectly fine. I do it all the time, myself.
The biggest benefit of the reamp box is the ground lift which can sometimes help fix certain specific noise issues. Depending on a number of factors, the attenuation from the reamp might be better S/N-wise than just turning down the DAW output digitally, also. Both of these are kind of “try it and see” things, and as with most things, good enough really can be good enough.
I strongly suggest just plugging it in with simple guitar cables. It can and does work in many situations. Only if there are real noticeable problems start looking for solutions. It may turn out you need to buy a reamp box after all, but if you don’t need to spend that money...
