LaMonte,
Back in the early to mid 90s, before slides, when lifting the bed was the normal access used for engine service, most Beavers had support struts for the bed platform, although they were not very effective. Also then the entire bed platform was hinged at the headboard, so you could lift the bed without bending the mattress.
However, since most coaches with slides rarely need the bed lifted. Also the bed platform is hinged under the mattress, and lifting the bed platform can damage an innerspring mattress by bending the wire spring frame, therefore the mattress is usually removed to access under the bed, and removing the mattress makes lifting the platform very easy.
Gerald