I’m not confident that it’s possible to make a kaeth drunken, and/or whether they would still be unwieldly in such a state if it existed.
(Linobir, though…)
Joke aside, I imagine that the main problem with scooping a nebula is that even the “dense” ones barely have anything to scoop, but given that the time-to-refueling is probably measured in megayears… they can probably afford going relatively slowly.
(For values of “relatively” that still mean assembling somewhere on the order of a moon’s worth of hydrogen per year. Stars are big.)