Discussion about the Korg PolySix synthesizer

OK, I have decided to make a modification of the LFO range, but it 
seems like this modification was only mentioned in passing somewhere, 
so I will have to be intentive here, and would appreciate any help 
from seasoned PolySix modificators. 
The idea is to make an alternative frequency range available by 
augmenting the LFO speed capacitor with another with a smaller value. 
I want to be able to take the LFO into the audio range. Any good 
suggestions for an alternative cap value? Maybe 1/10th of the 
original cap value is suitable? Could/should an even lower value be 
used? I know from the MiniMoog that the faster the modulation 
freqency, the wilder it will sound. (My best Mini modulations are 
with osc3 in positions 8', and especially 4').

To make this a reversible and switchable modification, I plan to 
replace the LFO speed pot with one of the type that has a push-pull 
switch inside too, so that by pulling the pot the LFO goes into the 
desired FM range, pressing it returns to normal range. This could be 
achieved by putting the new small capacitor in series with the 
existing one and using the switch to bypass the old capacitor, 
leaving only the new smaller one in the line. 
Any comments to this. Anything I should be aware of before I do this?

Thanks

Frank Carvalho