Thanks!
Macromodels with 2 or 3 periods

I guess it depends on the subfield. If your subfield is quantitative, many people will consider finite horizon models too simplistic and often sneer at them. But your subfield is more "puretheory" oriented, simple models do not seem to be discounted so much. (Granted, puretheory macro papers are much harder to publish, especially if you are an LRM)
This is the correct take.

I think the preferred way is to isolate the mechanism, perhaps using two periods and a partial equilibrium setting, and then put that into a proper DSGE to show that it still works in a GE setting,
Finite horizon vs infinite horizon does not have any relevance for GE (or D, or S).

I think the preferred way is to isolate the mechanism, perhaps using two periods and a partial equilibrium setting, and then put that into a proper DSGE to show that it still works in a GE setting,
Thanks! What if I solve for GE in closed form in the 3period model?
Then the referees will ask for the infinite horizon version.