John, your angle grinder with flap disk mounted to table reminded of another method I used. Put a slightly worn (rounded, worn circumference edges) grinding disk on it. You can do real fine fit-up grinds on tube ends with it.
I do most tube ends with radius-ed bench grinding wheel, then fine tune, if necessary, with the mounted angle grinder w/ grinding disk.
I've seen guys doing the shaping with aviation snips and rat-tail files, but those methods don't work for me.