I advise against making the change.
First of all, not every "molded case" breaker is designed with motor protection in mind. While this is something that usually comes up in 'motor control centers,' rather than combination starters, it is something to consider.
More important, fuses respond much more quickly than any breaker; this is why some equipment specifies 'fuse,' rather than simply 'overcurrent protection.'
It is so tempting, so easy, to see a blown fuse as an inconvenience, to blame the fuse. Don't forget that when a fuse blows, it does so for a reason .... too many see their job as 'changing the fuse,' rather than fixing the problem that blew the fuse in the first place.
Review the application as well; many times the wrong fuse is installed.
