The VR80 comes from the factory with a commercial two-piece buffer tube, designed to attach to the factory thumb-hole stock for importation purposes. This new adapter is designed to allow you to upgrade to a one-piece Mil-spec buffer tube, so you can use any Mil-spec AR-15 collapsible stock. This spacer will allow the use of a Mil-spec endplate or an aftermarket AR-15 quick-detach sling swivel endplate.
Ditching the stock plate and screwing on a Mil-Spec tube:
If you just toss the end plate and screw on a Mil-Spec tube, Then you're just screwing the castle nut directly against the receiver. The adapter plate also captures the pin that protrudes from the receiver. If you screw the buffer tube in directly, the buffer tube can still twist loose.
If you use this adapter plate AND an end-plate (like on an AR-15 setup) you can also stake the castle nut so it wont move.
Modifying Stock Plate:
You can do this but risk damaging the stock plate and having to buy something to replace it anyway. I always encourage people to try new things, but even I don’t like modifying my stock parts.