Sorry, by "customize" I thought you were just referring to the existing option in settings about whether you wanted it to play TTS or syllable-by-syllable.
As far as when, it's tough to say - depends on how many other requests we get and on whether or not anything else shows up (additional audio options, e.g.) that might make it a more critical feature for a larger number of people. I don't think it's likely to happen in 3.2.13 since we're already adding a couple of new things to that on top of what we did in Beta 1, but hopefully within the next few updates at least.
A draggable menu would be relatively easy to add to this control if we already added one somewhere else, but the work of adding the first draggable menu to our Android UI would be substantial and at the moment I'm not aware of anywhere where it would do enough good to justify the effort.