interesting views from everyone about this subject
A round grate in a square stove CANNOT be better
Dump grates where made on purpose to dump the firebox into the ashpan if you ever let the fire go out.
Being able to shake the stove without opening the ash door is BETTER
Being able to view the lower section of the firebed as you shake is BETTER (Antique stoves like Glenwood had this mastered with their lil' 3rd. shake door and mica stoves which allow you to see the "glow")
Clinkers have always been a subject of grate design and they will always exist to some degree with coal burning (opening draft prior to shake may help soften/burn the problem, placing cast fingers at the bottom of firepot may help free them "Antique's", Placing a cast ring between grate and firepot may help reduce the jamb by lessoning the gap "Chubby", designing individual apposing cast slider grate system that allows for some play between each and every sliding finger grate that lets a clinker get through if needed may help "Crane 404", creating a funnel effect to the grate so clinkers tend to head towards the center and not towards to edges and many other ways to alleviate this issue (that will always be their) have been attempted to some degree or another and its personal preference as to which helps the best.
Typically folks on this forum don't let their fires go out very often so having a dumper grate is pretty mute for most of us.