Just my personal view, Arch, but I drill a 1/2" or larger hole to the depth of the jar or vase bottom (not sure what you're working on) and then use my (Oneway) termite from the bottom of the hole up... works well without any special gear like braces, tow truck, arm reattachers or anything... *g*
Again, just my OHO, but if you need to change from a turning process to a milling or boring process, why bother turning??
I could mass produce bowls by drilling stepped holes with forstner bits to have a preshaped bowl to put on the lathe, but what fun is that? I treat this as a hobby and the joy is in the trip, not the destination..
An alternative is to buy a used metal turning lathe and pre-cut all of your blanks before putting them on the wood lathe... 100's of identical goblets, uniform shaped bowls, etc... End grain would be no different than cross grain to a machine tool.. Mac