Thanks for that excellent feedback.
I'm no climatologist -- never even played one on TV -- so recognizing the impact one land mass or one terrain feature would have on other areas of the map is not something I'm all that good at. In fact, I've come to be pretty sure now that some established "facts" in my world are, in fact, climatologically incorrect, but they've become centrally important to the game as played so far so I can't just "fix" it now. Fortunately it's a fantasy world, so if anyone asks I can just say "Magic did it" and move on.
I'd rather avoid doing that in the future, though. I do have three other continents, one of which we've already seen a significant chunk of it (and it's not really all that hard to explain oddities in the climate of a continent that is being perpetually ravaged by trans-dimensional magical storms); that still leaves two continents that are basically clean slates for getting the features right, though, but I'll need help fleshing out those details correctly. Fortunately, I've got time -- my only pressing need at the moment is the region the party is exploring right now.
In general, I do like my worlds' politics, economics, and geology to make sense rationally, albeit with a few magical liberties here and there. So I really do want to design the remaining two continents to be sensible and plausible, continents that one could actually find in the real world. Those will start to show up in the WIP forum, after I've gotten the current region to a more-or-less complete state.
Glad this thread was made, was wondering the same thing, so would like to say thanks for the answers as well