First of all, I'm vehemently against ANY requirement, not just "improved training requirements", to possess a concealed carry permit. The difference between open carry and concealed is a little as a long coat. Open carriers are not required to demonstrate any skill level beyond basic velcro fastening, so why, when you move the handgun from outside the waistband to inside the waistband, on constitutional consideration alone, does it require "training requirements"?
Secondly, the phrase ["defensive handgun skills" includes]...INCLUDES...way too open ended. Depending on the whims and fancies "issuing authority", Portland may set the goal posts so that even the sharpest scopes couldn't see them.
And, finally, the "issuing authority", defined in this legislation, is at the municipal level. Maine has "exempted" all municipal gun laws (with the exception of regulating the discharge of firearms within city limits, city properties, etc.) specifically to guard against the creation of a hodge-podge network of local gun ordinance provisions/restrictions so that Maine citizens are treated equitably across the state.
Here's an incredibly radical idea...let's leave the gun laws alone...and start ENFORCING them...and see what happens.