Anyways, just to explain myself a bit.
Most of it came down to oxygen exposure. I used a glass carboy because it cannot be permeated by oxygen, unlike plastic buckets which are extremely permeable (which also would lead to a permanent infection afterwards, unlike glass). I used a really small one for similar reasons, to minimize headspace.
So how does this point to lambic? Because the above are reasons why a 5gal glass carboy is a popular choice for secondaries, but almost never primaries. They are only major concerns over extended periods of time, right? Thing is, lambic really needs to age for at least a year (this one will have 3 years), and secondaries are specifically not supposed to be used when fermenting lambic - the autolysis which one would normally avoid by racking is actually something you want to expose a lambic to.
So ultimately, it makes a ton of sense to choose what is normally an ideal secondary vessel instead of an ideal primary, because, while you deliberately don't want to rack off the yeast cake, it's also EXTREMELY important to minimize oxygen exposure, especially since the more oxygen a lambic is exposed to, the more acetic acid will be produced.
