Gain issue when using [slide] to remove clicks

I'm having an odd problem with this harmonic oscillator I'm working on. As I increase the partial (multiplier of the sine wave frequency), the gain decreases... unless I remove everything I put in to avoid clicks.

What am I missing? If slide is basically a filter, then I think I get why it's happening, but it also does it if I use the go.line.msor go.line.samples abstractions, so I'm stumped.