The following does not work:
LISTEN 'foo%'
Neither this:
LISTEN SIMILAR TO "foo%"
This works:
LISTEN "foo%"
But it does not act as a pattern.
We could change the SIMILAR TO something like following (accepting also type of the pattern), for example:
LISTEN PATTERN 'foo%' TYPE 'similar'
LISTEN PATTERN 'foo*' TYPE 'ltree'
Or
LISTEN PATTERN 'foo%' USING 'similar'
Or
Or