Trust me.. I know ALL about those "kinks".
Last week I managed to figure out a Monophonic Mode and Portamento for my ongoing Seenthysizer project.. the Teensy 3.5 board/chip.
I made a video of the key action I was trying to explain where it "trills" a note back and forth.
https://youtu.be/WEmxM_Wb44oI also just began to figure out how to get a Pitch LFO modulation to work.
I intend to make the Portamento mode even more interesting later on when I phase the timing for each of the seven voices... so they all begin to glide a few milliseconds apart to fatten up the sound.
/Blaine