Wow... you like asking questions where the only correct answer is "it depends" or maybe "yes and no"
Generally, tube amps will have larger values than solid state amps. This is because tube amps are usually by nature high-impedance, and solid state amps are usually by nature low-impedance. One exception are the Sunn concert lead/bass amps that use FET's in the front end, and since FET's are high-impedance solid state devices, can use the exact same tone circuit as the 2000s.
So in general, if your tone control values are "too low" for the impedance type of the amp, then you can "load down" the previous stage - reducing the gain and giving you a muffled or muddy tone, kind of like when you lower the volume control on your guitar and some of the highs go away.
Is there such a thing as too high a value?
Play with your bass control. You will notice that it starts off increasing the bass fairly rapidly, but then the amount of increase you get slacks off to almost nothing by the time you get somewhere less than half-way. This is a 1M pot - Fender amps with essentially the same circuit will generally use a 250K pot. With the tone stack circuit, the extra resistance range of the 1M pot is usually not needed for maximum response. So if you thought about putting in a 2-10M value for the bass control, don't bother.
Play with your treble control. It will pretty much do as you would expect... acting like a volume control for the treble. This is a 250K pot. Slap in a 1M pot and the control will function differently... from about 7 up to 10 it will act much the same as the 250K pot, but as you get around the middle of the range it will start acting as a "treble-bass balance control", giving the perception of boosting the bass below a setting of about 4-5 on down to zero, and reducing it between about 5-7. A see-saw effect between bass and treble. Try out almost any Vox amp as an example (Vox tube amps usually use a 1M value for both bass and treble controls).
The value of the middle/contour control, sets the overall "insertion loss" of the tone circuit. See... you are not really boosting bass or treble with those controls, you are really just reducing them less - another one of those backward things where we perceive things opposite of what is really happening. Fender will generally have a 10K here, Sunn & Marshall will generally have a 25K. By swapping in a larger value, the overall effectiveness of the treble/bass controls will be reduced - the boost or action of the controls will not seem to be as much, and if you go high enough in value, they will seem not to work at all. Some amps provide a switch to disable or disconnect the ground connection to the middle control - an infinite middle control value, effectively making a tone bypass switch.
To recap:
1) Values of controls within a certain range won't really make a drastic change. You can change the response or "feel" of the controls which may or may not be to your liking... but you will not find a bunch of magical tone in changing values of the controls.
2) Tone controls change the frequency response of the input signal based on what they subtract out. They cannot put something there that isn't there to begin with.
e.g. By changing the .022 contour cap value to .012 you are not subtracting out as much of the upper bass/midrange frequencies as you were before.
