Leeds fans seem to be in denial about how weak your matchgoing support has been during your history compared to peer clubs. Even at your height when the Capacity allowed plenty of over 40K attendances, your fans couldn't mamage 40K+ over a season. No excuses will change that.
I appreciate Leeds' support has grown over the decades and if the Capacity allowed it now, you'd easily get over 40K across the season.
I reckon as a PL club, 53,000 will be about right for you, but if you go down again, it could be a risky move for the club financially as you won't sustain 50K+ crowds if you stay down for a prolonged period.