U1 power supply fan swap.
So, for my particular arrangement, I have my U1 on the desk with me, just to the left of my monitor. The printer was built to a price, we know that, and some components didn't get a lot of money put toward them. The power supply is horrendously loud and vents directly through the right side, which faces me. Changing out for a Noctua fan is such an improvement; I really didn't expect it to be as significant as it is. I considered using the low-noise connector adapter (reduces fan speed) included with the fan, but in the end, I just ran the fan normally for peace of mind that the PS had adequate cooling. One thing to note is that the 4-pin to 2-pin adapter cable I got on Amazon had the polarity reversed. This caused me to tear down the whole thing a second time. This time, I quickly plugged everything in so it would boot up and verified that it spins.
I don't feel like the reduced speed would have made it quieter to an amount that would offset the reduction in airflow. I'm extremely happy!