Originally Posted by
xliioper
Not as much domestically because most FC fares are dual-inventory and coach availability also factors into FC fare availability with those. There's P bucket open on the 6:30AM flight below, but the cheapest FC fare you can book is a V-basis FC Z fare because there is only V open in coach. This effectively prevents fares from getting upside-down in most cases.
Yes, understand the domestic (2-class) situation has mostly been address, it was more of a reference to the past. I can see some barriers to that approach for the 3-class flights.