I either take the hard-sided container, or I do without the smashable, squashable, smooshable, and squishable!

[That was a hard one to type. Short recess while I utter a number of unladylike words about autocorrect!]

This practice works out, because those 4 S foods are great for short trips but don't do well on longer trips, having a tendency to mold or get stale with age or (from the bouncing) disintegrate into a soggy sorry mess. Some years back, I tried using the hard-sided container for peanut butter and jelly sandwiches for a 3-day trip. The first day's sandwich was great; the second day's was fairly good. The third day's PB&J was quite inedible!

YMMV and HYOH, of course!
May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view--E. Abbey