Hi Scott, I'm ordering a UM2ex next week and very much need to do this modification when I receive it. However, some of the information in your BOM is a little vague. You refer to the hex nut as a spacer/standoff, and there are good many lengths to choose from, could you provide the length of the hex nut? Also, regarding the M6 Heater Barrel for 1.75mm Filament, a link to one would be a huge help! There are too many options available to fit that description and I don't want to guess as to which to select. Thanks for discovering this modification and providing the information.