The problem with all anti-linktrail practices is that they make search (or
search and replace) in the source very hard. This relies both to bot owners
and humans who use the insource: regex search engine.
I think a brand new approach would be necessary.
For example, [[foo]]bar would behave as now, generate a linktrail, while
[[foo]|]bar (a pipe character between the ckets) not. Another idea would be
]]] (3 ckets), but it could conflict with embedded brackets suchs as an
image description with linked text.
Thus all antisemantic workarounds for avoiding linktrailing would be
unnecessary.
We should always keep in mind that we try to approach a semantic wiki
(although this is partial except Wikibase).