It took some finesse and me convincing lonelydumptruck to "give it just one more big shove" but it went in the space with the sound-baffle!
We've run it twice. The first time we discovered one of the hoses needed to be tighter (and we had to mop out the cabinet under the sink.) The second time one of the screws meant to secure it in the cabinet fell out (never to be seen again) but that is fixed it is onward and upward!!