Those parameters cannot, unfortunately, be configured in 1.0.x. You will need to change the source and rebuild (at least) the lib/com.springsource.server.serviceability.output-1.0.2.SR02.jar.
The package com.springsource.server.serviceability.output.inte rnal contains the class StandardDestinationRegistry which is the file you need to edit. This hard-codes a defaultRolloverPolicy with a 100 Mb file size and passes a literal 4 for the number of files when it constructs (in more than one place) a FileDestination.
Glyn Normington
SpringSource