Trigger on attribute without content type leads to string match

If I select an attribute without specified content type sing the add trigger wizard and simply step past "Configure trigger attribute" without setting either type or unit, then I am presented with a string matching for the value in the next step.

My intuitive feeling was to at least get some sort of number matcher (typically the max value). If I select any type I get that max trigger value matcher (adjusted to the correct type and unit).