Many riders with gaited horses think they don't need to do the 'common' dressage exercises, because they practice other gaits.
But a gaited horse is just a horse, it has the same muscles and the same bones and the same asymmetry. And no horse is made to carry a rider - no matter what breed, no matter if it's a gaited horse or not - because by nature most weight is on a horse's fragile fore legs.
So all core exercises of ST are needed for any kind of (gaited) horse to help the horse transform from natural balance - the picture on the left where the horse is caryring more weight on the front legs - to artifical balance - the picture on top of the ladder, where the horse is carrying more weight on the hind legs. And this rebalancing can take place by transforming the ability from the hind legs from 'pushing' ability to also a 'carrying' ability.
Now for a clean tölt you need free shoulders and hind legs that are equally strong. That's why tölt is at the same level of piaffe.
When novice riders start a new method, then - after practicing the basics a few times - they often say that "their horse gets bored".
Now, most of the time it's a projection of our own 'boredom';
When we are only practicing the 'names' of the exercise and not really the 'essence', that might lead to loss of interest.
Or when we are only concentrating on the WHAT of an exercise and not on the WHY, that might also lead to a 'dull' training.
Boredom also comes from if we start to compare with yesterday. When we start to expect: when we stop having an open mind for all the tiny details, when we stop being just interested in what happens, when we stop having a beginner's mind, when we stop appreciating.