Interesting idea. I think that would be a cool, "SuperEgo" kind of addition to the feature set. I don't know what it would take to "slew" the pitch detection, implement a glide time control, or what algorithm would be the best fit. Perhaps you're right: PitchFlex has many of the requirements already. It'd almost be like triggering the FLEX switch with each incoming note.
I've toyed around with the H910/949 algo and gotten some glide effects. It's not too predictable, and – of course – I couldn't quite reproduce it when I sat down to come up with a "recipe".
The other way that I've managed was with the Harmodulator and envelopes. As long as you keep the sensitivity high, and the input signal constant (highly compressed, or active playing), there's no glide. Clamp down on the strings for a moment, and the glide will trigger.
GlideUp
Mix = WET:100
Pitch Mix = A10+B10
Pitch A = A:-1oct
Pitch B = B:-1oct
Delay A = 0 ms.
Delay B = 0 ms.
(encoder) = HMODLTR / TMP OFF
Depth / Key = DP: +1oct
Speed / Scale = SENS:10
Xnob = ENVELPE
Ynob = FBK: 0
If you want to glide downward instead, you can only use one pitch shifter. That's because of the shifting implementation in the Depth / Key control. You can't get the PitchFactor to alternate up and down pitch glides without an external control, but you can get both pitch shifters gliding in opposite directions simultaneously [ see comments below the preset ].
GlideDown
Mix = WET:100
Pitch Mix = A10+B0
Pitch A = A:+1oct
Pitch B = B:-1oct
Delay A = 0 ms.
Delay B = 0 ms.
(encoder) = HMODLTR / TMP OFF
Depth / Key = DP: -1oct
Speed / Scale = SENS:10
Xnob = ENVELPE
Ynob = FBK: 0
If you want to hear how gliding up & down sound together, take the GlideDown preset above, and change the Pitch Mix = A10+B10. Use an Aux switch or expression pedal on Pitch Mix to change between up & downward glides. There's not a lot of control over the rate of the glides here, but you can control the starting & ending pitches. I stuck with the safest intervals [octaves], and 100% Wet to highlight the glide effects.
