400 feet is pretty low for big sequence maneuvers. I don't fly pattern but fly scale aerobatics. Even with the small(er) 1/4 scale planes that I fly I KNOW I am way above 400' often, all while staying in the box.

http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/1acfc3f689769a56862569e70077c9cc/$FILE/ATTBJMAC/ac91-57.pdf

-Cheech