Tbh., both ideas are somewhat tricky.
I think a tropical forest just won`t work without trees in the skybox, which I am not doing yet. It`s something I plan to look into sometimes though, since it would open up new territories to cover.
Swamps, I think we already talked about it, maybe on the other thread. It`s not really leaning towards the easy environments/skybox thing.
Stonemason`s jungle forest set might work as a swamp if you add some water though.
That aside, sorry there haven`t been any new sets lately, had a somewhat bad time.
Right now I am re-building the next easy environments set for the third time, but it seems three is the lucky number indeed, I hope to have previews soon.