The biggest QoL thing for me is super specific but I've been playing a lot of AST lately and I wish the CD on Spread could be reduced a tiny bit - even if it's just like 25 seconds instead of 30.
This way when you Sleeve Draw and get a Balance in your Draw and a different card in your Spread you can ditch your Spread card but still retain your drawn one. It wouldn't have a huge impact but it would make me happy.