Our rogue tabaxi is moving 120 feet in a round with that feline burst of speed. That's the right to do it, yes?
Feline Agility
When you move on your turn in combat, you can double your speed until the end of the tum. Once you use this trait, you can't use it again until you move 0 feet on one of your turns.
So, in effect the rogue (assuming speed 30) can move 180 feet in a turn=
Feline Agility = double speed = 60ft
Move = 60ft
Action = Dash = another 60ft
Bonus Action = Cunning Action = Dash again = yet another 60ft
= 180ft
However the tabaxi can't use feline agility and double their speed again until they've moved 0 feet on their turn.
So, they can do the feline agility thing for one round, and then they need to catch their breath, as it were- still 180 feet in 6 seconds, that's worth thinking about, and then putting to the test.
Cheers goonalan