I got this idea while playing around with an Angel/Bob/Py mod pack in sandbox mode and realized something: We have an item in vanilla that lets you spawn in infinite items and acts as an item void, but don't have something to do that for fluids. I know you can achieve something similar to what I want with barrels, but what if you don't want to deal with setting up a barreling/unbarreling system just to test a refinery setup or want to screw around with Angel's Petrochem without dealing with a mess of barrel-filled belts.
A quick google search has already revealed a mod for this, but it's horribly outdated/abandoned, and I have zero modding skills.