Types (such as for :type or @jsdoc types) in GMEdit are assumed to be global, which means no constructors in events / functions / other constructors.
You can use /// @hint to describe any types that GMEdit didn’t pick up automatically.
Long-term I would like to support more esoteric uses, but realistically most of the time that I spend on GMEdit is now used to fix endless YY format compatibility issues that each new IDE release introduces.