LAN LANPASS - Standby for earlier flight - Allowed?

Just curious. I'm booked on the late departure from LAX-LIM-EZE on LAN in Business Class (discounted I). I may finish work early and head to the airport in time to make the earlier departures leaving around 1 PM, but won't know if I'm able to get there in time until about the day of. Which makes me wonder, will LAN let me fly on an earlier flight if there is space in Business when I get to the airport or will they want to reissue my tickets at a higher full-fare business class price to do that? Just curious, because if it's a definitive NO then I won't even bother to try to and finish earlier to get to the airport only to sit around about 9 hours before my flight.

Thanks to the LAN experts out there who have experienced what many seem to describe as "pretendy" rules by ground staff. (love that...pretendy...haha...I think United is also fluent in "pretendy" rules btw, but at least on UA I am more versed in the real rules).

You might note that there is a large price differential with the night flight being much cheaper than the afternoon one. Knowing how LAN functions, I would say that you won´t have much of a chance of getting on that earlier flight. J fills with LanPass upgrades.

My experience says: "NO". They generally go strictly by the book. Unless you want to pay change penalty plus fare difference you are probably out of luck.