Need NB Designer plugin modified to show width and height of custom text in mm

Hello, We are using NB Designer plugin to allow customers to make custom text they wish to engrave on phone case. We need an SVG file created of the text created, as well as the exact height and width of the text in milimeters as well as the exact position on the phone the text is in milimeters. We already have the phone cases designed to the exact measurement and size of the phones, so we just need to be able to download SVG of the text customers wish to have created, in high resolution.