The standard thumbscrew grips in the USM-VB stop at a minimum of 55mm.
However, it’s not a problem for us to make a USM-VB using the longer USM screws. The suspension will be a special order item.
Description: InVision USM-VB (Fitted with USM screws)
Order Code: 044912
The performance will not be affected by using longer screws.
The 900g+ of the Charter Oak is getting to the limit of the weight the USM & USM-VB Lyres will take. It'll cope fine as long as the mount is used vertically, but if it's angled then you'll see some sag. The problem with the sagging is if the inner support ring touches or knocks the outer ring, as it'll cause noise. So in short, fine if it's held vertically.