Viltrox released new firmware updates for their Nikon Z-mount lenses that optimize focus performance, improves lens stability, and adds some bug fixes. The new firmware updates can be downloaded here (select Z-mount from the sidebar).
A detailed list of Viltrox lenses pre-order options and a 10% coupon code can be found here:
The new Viltrox autofocus lenses for Nikon Z-mount are now in stock