With all due respect ABYC doesn't issue standards. They have no authority to do so. But they do suggest.Yes, but there is a shore power circuit on the boat, and that is the one ABYC standards apply to, and where they say an ELCI is required.
There is a search voltage setting so if set to a 60 watt light for instance it will turn on but not for a 40 watt light.
The draw of the LED green light is way less than the 40 watt bulb.
Not experienced with inverters, but sounds like you mean "current" not "voltage"? Both bulbs require same voltage but different current draw. Since I don't know inverters, maybe they are determining current load by some internal voltage measurement that could be part of a protection circuit or something like that.