We are rarely early to the airport and almost always have checked luggage (both MVPG). The 40 min cutoff is a hard deadline and we've managed to get bags checked with a few minutes to spare but never after 40 min. We weren't able to get everything into carryon bags on an OGG-ANC flight a few years ago after some delays getting a shuttle from rental car agency (and cutting it close, as usual) but the agents were very nice about booking me on a different flight an hour or so later so I could travel with the bags. They also let us check all three in my name without fees so I didn't have to lug a box of pineapples around during my newly acquired layover. Sent the hubby on his way and met him in ANC many hours after he arrived!! Lesson learned for sure on that one but we also got lucky with great agents helping us fix our mistake.