Example patch using drawable OSC and LFO techniques, explore, learn and improve on it, or just use as is! I've used WolfShaper plugin as shaper for demonstration, it's free (find on Github), but you can also use MWaveShaper if you want in it's place, look at notes in the patch for more details.
Example patch that makes use of waveshapers (which can behave like MSEG) to create custom OSC and LFO shapes and apply them polyphonically in Poly Grid. Beware - this technique can be a bit CPU intense.
Took me a while to prep this for public usage (including some notes and instructions on how it works), default requirement is WolfShaper plugin that you can find on Github. or you can put your own waveshaper in it's place, there's one each in OSC and LFO layers inside Note FX chain. by x.iso