check accepts 'x' + if ... that mx check rejects with CE0117 #1710

What happens: declare $L String = 'x' + if $c then 'a' else 'b'; passes mxcli check, but mx check fails with CE0117.
Expected: the expression checker matches mx check, or at least warns on an if-expression without parentheses used as an operand.
Version: 0.28.0. Still the case in 0.29.0: mxcli check says "Syntax OK" and "Check passed!".

Mendix 11.12.4.