Idle in a separate state won’t work; it will clamp your anims right but then at low movement speeds the capsule will just slide around in a stationary idle pose!
Rewriting the CMP would probably work if you’re willing to get your hands dirty, but I really do feel like clamping the input vector length will work.
Obviously there exists, for your character, some acceleration value that will take you from 0 to 150 quick enough that the anim blends right. It will take some experimentation, but clamping the vector to correspond to that value minimum if it’s above zero (with 1 being the upper bound of that range and also equivalent to your max accel rate) will definitely work.
And it will also probably make things feel smoother since it won’t lead to situations where the player bounces from 0 to 150 in an instant and then moves from 150 to 160 the next instant (which might be fairly jarring).