[[Tables in WikiText]] is one construct for which the open tag blank line "trick" cannot work. In order for the parser to recognise a table row, the entire row must be on a single line.
Adding a blank link after an open tag within a table cell causes the row to span mulitple lines and the parser ceases to be able to recognise it as a table row.
The only way to get [[block mode|Block Mode WikiText]] punctuation recognised in [[wikitext tables|Tables in WikiText]] is to use <<.wlink TranscludeWidget>> with <<.attr mode>> = <<.value block>>.
Note that <<.wlink MacroCallWidget>> does not have a similar <<.attr mode>> attribute and the content of macro definitions can only be parsed in [[inline mode|Inline Mode WikiText]]
