I was tempted to use "one-twelfth of an inch" or "one-tenth of an inch" in
Amorphous instead of "one-eighth of an inch."
A gray ooze isn't given a size in 5E but in earlier editions they are usually 4 to 12 feet long and 6 to 8 inches thick, averaging about 8 feet. The 1E AD&D version specifies they are long and narrow (the largest are "fully 3′ wide and 12′ long") but they're just "long" in 2E. They are round in BECMI.
The 5E gray ooze is Medium size, so if it it were, say 6 feet in diameter while being able to easily fit through a one inch gap, an enslaver is eight times smaller at nine inches diameter. Which suggest it can manage gaps of one-eighth of an inch without squeezing.
If a gray ooze 8 feet like in BECMI, a nine-inch blob is 10⅔ smaller, which means one-tenth of an inch if we keep the proportions, but that just seemed an odd ratio to me, which led me to wonder about using 1/12th.
Checking around the doors in my house, most of them have at least some areas with 1/8th inch gaps, but a few are tighter fitting than that.
Come to think of it, the Enslaver can just use "
Squeezing into a Smaller Space" to fit through a narrower gap, so I'm not sure why I'm fussing so much.
Apart from that I've got too much spare time today!