How do I undo damping? [Sytrus][Synth]

An example would be using a square wave with pluck enabled. Set DAMP's envelope to this shape of a W. The harmonics will fade out, but not back in! We shouldn't be allowed to have positive slopes in there when it is effectively a zero slope.

I haven't found an accurate way to link a cutoff filter with an operator to only remove certain harmonics. I was able to come up with some almost functional workarounds:

1. Syncing a filter's cutoff frequency to KeyM is a terrible/inaccurate work around to this.

2. Indirectly filter using this method: Having a duplicate operator with inverted polarity isn't flexible/powerful enough and still brings me to the same point of not being able to automate/modify the harmonics instead of frequencies.

3. Sampling and reversing the samples would be a huge waste of time.

Workaround 2 is the closest I've gotten. I still can't make an EQ/filter that's synced to KeyM