Personally I've solved this by installing linux.
Linux uses yaboot to provide a boot menu, which I then manually edited to included an entry for MorphOS.
Word of warning though, the bootmenu is a forth script and messing it up will lead to a situation where you need to manually give the boot command from the OF command prompt before you get the chance to try fix it. So this clearly is only an option for the expert users who know their way around OF prompt, linux and modifying existing forth scripts.
