9ft long hone extension shaft

[Frank S]

Yes, very good intermediate support, guaranteed it would whip under load and/ or RPM.
Especially with honing in a different county than motor driving it.

PS; edit in. Supports work in lathes too, with proportionally thin material in the spindle [spindle liner/ bushings] and outboard with rolling supports, often simple as V-cut pieces of wood.

word of warning when spinning small diameter long pieces in a lathe if they extend beyond the back end of the spindle. It is nice to have either a bushing the size of the spindle bore to fit the part or a chuck or just 3 simple grub screws spaced equidistant around the end of the spindle.
if their diameter is small enough then probably should have some support even if they only reach halfway to the end of the bore.
any shafts extending very far out the back end of the lathe needs some form of support .
Like Tool maker 51 stated sometimes just a V block will suffice. If high RPMs are involved then it needs full containment. Think whip stock . sometimes more than one support may be warranted. When things go wrong on a lathe they don't go wrong right now they go wrong long before right now almost as if pushing time backwards enough for the effects to slap you in the head before it actually happens.