Sorry I wasn’t clearer and more informative.
Your stomach isn’t absorbing glucose, it’s holding the food and processing it for the small intestine. Drinking slowly or quickly isn’t going to make a difference - your small intestine is going to get the chemically dissolved mass of nutrients in bulk, they don’t trickle in at the rate of ingestion. The iso is partially digested by the time it hits your small intestine, and then over the course of 6-8 hours it passes into your large intestine.
The stomach doesn’t trickle food out at the rate that you take it in - it takes in whatever you eat and over the course of a couple hours mixes and churns it with digestive juices, the shunts the bulk of your meal out into the intestines to take their journey into the municipal waste system.
There may be a psychological benefit to eating more slowly, in that you will feel more satiated, and there may be an impact on insulin production in response to ingesting food slowly rather than slamming it. But… if your insulin production is normal, then while the Soylent makes its transit through your guts, it shouldn’t matter physically whether you chug or sip.