Welcome Finpod to your 24/7 live owners manual. This may have already been done but if not your back will tell you after your first sleep. Replace the mattress if it is the original, we did so after 3 sleeps on ours - i think it was more comfortable sleeping on the ground than on the original mattress!
Also, after 7 years we finally got smart and replaced the seat cushions with a higher density foam. Again, even though I am of normal weight I don't like my buns sitting on plywood; very little density in the original foam cushions. The foam we replaced with is like night and day difference. Even though we usually boondock, I like a few comforts after hiking/biking all day like a 'comfortable' seat and bed. Enjoy your 178!