In my opinion, the only times it makes sense to go for 30 Chests is:

1. You're playing way above the chests you're earning (ex. Earning Bronze while playing in Gold). ECR is a limiting factor and using more than 25% one day means you need to use less on another day or you'll be digging a deeper hole each day making it harder to earn chests.
2. You aren't able to play everyday. If you only have a day or two a week to play then play to your heart's content! However, even 20 minutes a day or so can yield more chests in less time than binging for 30 Chests at a time due to a combination of lower ECR and increased Rshares per chest.
3. Bragging rights!

At the end of the day, play the game however you enjoy it best! I just want to make sure everyone is informed and aware of how it affects their chest earning abilities.

Thank you for the upvotes and comments!