Variable shuttle speed options

It would be great to have the ability to increase the shuttle speed by a factor other than 2.

I love using the shuttle function to review and scrub footage but sometimes 2x speed is too fast. I would love to have the option to increase the interval by 1.5 instead of 2, or even having the ability to slowly increase by a constant interval would sometimes be helpful.

I'm currently working on hour-long videos with captions and reviewing the captions for accuracy. It would be great to have the ability to slowly increase the speed during sections with little dialogue and slow it down during sections with a lot.