I think that now we have bezier curve functionality in automation lanes, the next logical step would be to have the sine tool make use of them. It would make modulation (for example EQ filter sweeps for notch filters in Frequency or other EQs that support notch filters) a lot easier, particularly when it comes to adjusting the depth of automation, if there were only automation markers at the peak & base of each curve to grab & move to adjust depth.
Either that or a global LFO plugin (as in Ableton Live) that can be used to modulate insert FX parameters on the given channel. This would be preferable, but an overhaul of the sine tool to use bezier curves would be a step in the right direction.
I have been trying to figure out if it is possible to do this with the Auto LFO MIDI insert but have not been able to find a way as yet. If anyone knows if the Auto LFO can be used to modulate EQ filter Freq in the Frequency EQ insert, on an Instrument track, please feel free to let me know.