Hoi,

First of all, as I mentioned, I understand why you'd not want to do it the complicated way. I'm treating it like an experiment to see if I can learn what a module does.

Here's what I used

1 a bipolar mixer for the subtraction Triplatt
2 a DC coupled ringmodulator. Boundary
3 a shift register. Maybe I'm wrong here, but I added an offset and treated that as zero point.
4 a CV controled slew limiter. Boundary