It accomplishes this from the mbr istelf. PQ Boot requires a rebooting after the OS selection is made. Plenty of them. One can easily crash a hard disk. This is why having a rescue disk and good backups is so vital.
Disaster looms if partition boundaries are inadvertently overlapped.
It is a safe way to proceed for the novice since it provides clear graphic images of various partitions and will not permit fatal partition boundary errors. It also allows one to hide and set active whatever partitions one wishes. One may also use Partition Magic to adjust a partition's size even if it already contains data. Drive letter assignment problems may appear when one runs several OSes. Imagine that you have most of your applications files in the third partition whose volume is DATA on the master drive.