I've got a DYMO 450 Turbo hooked up via USB and CUPS on a Raspberry Pi 3 running Ubuntu Mate 16.04.2. It prints immediately for the first print, but has a delay of 8-10 seconds between every job after that. My buddy and I have been searching the internet for over a week trying to find a solution, but haven't found anything that works.

I've tried a suggestion you made to another user of adding the 0xVENDOR 0xMODEL unidir, but that didn't work (0x0922 0x0021 unidir).

Noted from the syslog, it appears the printer disconnects between jobs:
usblp0: removed

The driver I have installed is from http://www.dymo.com/en-US/dymo-label-sdk-and-cups-drivers-for-linux-dymo-label-sdk-cups-linux-p--1#

Any suggestions?