Totally agree. I'm not saying it is easy at all. But I'm not sure it would be difficult to implement a system that has parity with the the way that league home games are sold and uses historical purchase history the way in which they sell the away games.
If you buy 13+ in a season, you know you will get 13+ the next season, and the next season and the next season forevermore. The only way you don't get over 13+ now is simply by being unorganised/missing a sale or losing your income. There are people who have every European game going back years and there is a chance, however remote, that a combination of bad luck in terms a ballot, then missing a quarter final, then the first game of the next season being say, Real Madrid, that they could be off the ladder. This jeopardy doesn't exist on the other ladders so long as you continue to attend. Have parity on all the ladders.
100% If you're going to have guaranteed tickets for the PL when you have a certain amount of home credits, then it should be the same for the ACS in the Cup competitions. People who have been to all the European homes for years could end up getting screwed, same goes for the FA Cup if we draw a big team in the 3rd round.
It's rubbish when people say it then turns into a closed shop if the ACS is guaranteed for the following seasons. There's still plenty of tickets available and I know people who have managed to get full home credits without the ACS, they just choose not to be on the ACS. It's the same for the PL, if you're not on the magical 13+, it doesn't mean you won't get a ticket and it's a closed shop, I've had plenty in my time without building up the magical number of PL credits.
Hopefully things will change for the 22/23 season.