setting compression on individual columns of astropy table

Is there a syntax to set compression on individual columns of an astropy table? In the following example, using all_array_compression compresses the columns, but using AsdfFile.set_array_compression() does not.

import numpy as np
from astropy.table import Table
import asdf

t = Table(data=dict(col=np.ones(1)))

with asdf.AsdfFile(tree=dict(table=t)) as af:
    af.write_to('test.asdf')

with asdf.AsdfFile(tree=dict(table=t)) as af:
    af.write_to('test_compressed.asdf',
        all_array_compression='zlib',
    )

with asdf.AsdfFile(tree=dict(table=t)) as af:
    af.set_array_compression(af['table']['col'], 'zlib')  # this has no effect
    af.write_to('test_compressed_col.asdf')

Comparing test.asdf with test_compressed_col.asdf, we see that they have identical checksums (and there's no zlib tag at the beginning of the binary block). So the set_array_compression had no effect.

I've tried variants of this like

set_array_compression(af['table']['col'].base, 'zlib')
set_array_compression(af['table']['col'].data, 'zlib')

but I couldn't get it to work.

I did dig around in the source code a bit, and it looked to me like it's trying to compare the ultimate ndarray base to check if two arrays are the same, but maybe a copy is being made somewhere that's thwarting this detection.

Start with the reproduced calls to AsdfFile.set_array_compression() and the table column expressions af['table']['col'], .base, and .data. Read the related source logic that compares ndarray bases, then reproduce the checksum and binary-block comparison from the example. Done means per-column compression works or the limitation and correct syntax are documented.