BTW today got contrary problem - need was Very slow - but was not able achieve this (set Duration Bias to 1 - it barely changed speed).
I'd still vote for more controllable speed adjustment.
In rest - one of the bests.
Update:
Ok sorry after experimenting with bunch of parameters seems was able to make slow.
But still prob regarding fast lol
Sorry you're having issues. I promise you, you can definitely achieve the speeds you want. I'll try to be very clear.
1 - Set the MIN duration to the fastest you want the cycle to go.
2 - Set the MAX duration to the slowest you want the cycle to go.
Setting those two sets the "range" of durations/speeds that the thrust can use.
3 - Duration Change Rate - This one is VERY important. When the plugin chooses a random duration (within the min and max you set), this slider chooses what percentage it actually uses to go to that new value. If you have it at 1, it will go directly to that new speed. If you have it at .5, it will go halfway to that new speed first. This slider is designed to prevent really abrupt speed changes, but, in your case, setting this to 1 means it will go directly to the new speed you want.
4 - let's go to the bottom of this section next. Speed HOLD Cycles Min and Max. This plugin ONLY changes speed after a cycle has completed and before the next one starts. Again, this is to prevent weird movements. It sets how many cycles have to complete before a new value is allowed. In your case, set this to just 1 for both. This way, when you do change the Bias slider, it will go to the next speed as fast as it can. I have no plans to allow for speed changes during a cycle as this will create bad motion behavior. But setting it to 1 means it will complete the thrust it's on and switch to the next speed immediately after.
5 - Duration Range Bias - If you set those settings above as mentioned, this slider should be much closer to what you want to do now. If you have it set to halfway, it will randomly choose durations/speeds from the entire MIN/MAX range. If you set it all the way up, it will just use the slowest speed. If you set it at the lowest, it will only use the fastest duration.
My suggestion for your case is to create a couple different presets that are triggerable in the scene. Preset 1, your faster speeds. Preset 2, your mid speeds. Preset 3, your slowest speeds. This way, within those you can still have variability but clicking a button then allows you to choose which speed you want at any time (with the caveat that the plugin still needs to complete the cycle it's on first).