That’s pretty big. Do you need something that large? My biggest concern would be that unlike a transition bag, it wouldn’t be flexible and it would sure hurt to stub your toe (or worse someone else to stub his/her toe).
Most people bring way too much stuff into transition, way more than they need. That would probably be a safety hazard b/c even though you put it out of the way, someone will find it and trip on it.
Reminds me of the dude next to me at my last tri who, no joke, had a recliner lawn chair next to his water bucket (for rinsing off his feet), and his stack of four towels. I respect his desire for comfort, especially since it was a piece of cake finding my spot next to his big ugly pile of stuff!