I took a look at Google Maps to try and visualize any alternatives and there really aren't any? The ramps to 9th and 10th would have to stay, and the only other thing I could see is keeping a ramp to Division and having Division traffic turn onto Van Ness to replace the 101 highway thru traffic access. But that really doesn't even solve any problems or make any more land available?
I agree very little new land would be made available. But Division likely would be restyled as a boulevard like Octavia Blvd with two express lanes each way down the center and one-way feeder streets on each side for local traffic. This configuration would still get traffic from Bryant to Van Ness relatively quickly, especially if the lights on Division were synched.
IIRC Octavia has a light sync setup that was designed to keep cars from rolling super-fast down the road, in concert with the somewhat steep incline from Market to Haight (which itself hasn't had that much of an effect).
When Mayor Lee proposed the removal of 280 in Dogpatch, local residents explicitly cited Octavia as a reason they did not want his plans implemented and instead specifically wanted the freeway retained.
I have read somewhere on this forum years ago that when the Central Freeway used to run all the way to Fell (and to Turk), the light timings for Fell/Oak facilitated 40 MPH continuous driving from the freeway towards Haight-Ashbury/Golden Gate Park; from experience I know Franklin Street (parallel alternate northbound to US 101 along Van Ness) has decent light syncing for about 25-30 MPH for through traffic, and pre-pandemic Great Highway was synced to about 35 MPH. Current Great Highway light sync speed is closer to 29 MPH, but not quite sure how fast.