Since the increase in speed is not linear but rather exponential, and added to the fact that the potentiometer (rate knob) is actually generating 16384 values internally (rounded for display only purposes to 256 values), and finally the fact that those digital values are converted back to an analog varying voltage before being sent to the LFO, which is actually a voltage controlled analog oscillator, one would be hard pressed to do so... Therefore, it will always be an approximation and there will always be some slight variations in speed, due to drift, and between one Voyager to another...
Despite being programmable, the Voyager is first and foremost an analog machine.
Analog electronics circuitry's behavior is not extremely precise. That's the beauty of it.
If you want to dial-in a frequency number for an LFO, and get exactly that speed out of it, you must use a virtual analog synth, or software emulation. On an analog synth, it will always be approximated. And in the case of the Voyager, the numbers between 0 and 255 (0 to 16383 internally) don't even reference the actual speed in frequency. You move the rate knob until the desired speed is obtained, and when you save that patch, the knob's position is digitized and remembered as a digital value for when you will recall that patch.
Now, that being said, one could always painstakingly measure the actual LFO frequency for each of the 256 steps of the displayed values.
But even then there would be a wide margin of error, since internally there will be 16 value changes before it shows up as one more number on the display, and the actual speed of the LFO will have changed (quite a bit at higher speed settings).
So, short answer to your question is: no.
BTW, haven't you indicated, in another thread, that you have the Old School version (serial 0263) ? There are no numbers on that machine... Unless you have an additional regular Voyager already ?