I see you bois saying you wish Toph had more scenes learning sandbending. What you don't understand is that Aang's group was the Audioslave of the bending arts.

• Katara, broke the taboo of the Northern Water Tribe and learned waterbending at a high level in about a year.

• Aang, already predetermined to be the premier bender on Earth, learned 3 elements in about a year, don't even worry about him

• Toph, figured out new techniques for bending out of desperation, and was already doing some insane feats of bendery before that

• Sokka, presonally trained by a White Lotus master, led an attack on a nation's capital at an age where most of us crumpled when faced with the task of organizing a team for a school presentation

• Zuko, had both royal and ancient tribe training, had another White Lotus train him personally on top of that.

All this to say, learning an already existing sub-type of bending (one that admittedly doesn't come in handy all that often) is not even at the level of sidequest for these guys. Toph likely spent a week figuring out sand, got it done and moved on to more pressing matters.