It really depends as much in life does.

If one is already on the street, getting off bike, hopping curb, walking carefully past all the kids getting on/off may not be much faster that just waiting and you still need to mix it up with the kids. Sure it is legal and can be done courteously, but is is really worth it? Consider as well the nice draft you get if you wait behind when the bus gets going again!

If you don't get on sidewalk and dismount walk past bus on street it is a bit silly (said as a judgment, not a fact) - it is also illegal (said as a fact, not a judgment)

This is such a minor thing to worry/debate about. Whatever you do walking or cycling the most important thing is to be courteous and safe to the kids you see and may not see getting on/off bus or crossing street in front of bus.