Strings v1.3 has all parameters controllable via MIDI CCs:
1: LFO modulation depth
16: Phaser LFO waveform
18: Arpeggiator pattern
19: Arpeggiator clock division
20: Waveform 1
21: Waveform 2
22: Waveform 3
23: Waveform 4
24: Pitch envelope depth
25: Phaser source mix
38: Gate on/off
39: Pitch LFO invert
40: Arpeggiator ping pong
41: Phaser LFO invert
42: Tie waveforms on/off
43: Waveform cycler on/off
72: Env Release
73: Env Attack
75: Env Decay
78: Pitch LFO waveform
79: Pitch LFO clock division
80: Env Sustain
81: Phaser LFO clock division
82: Sine Phaser frequency
82: Cycler clock division
94: Osc detune
95: Phaser depth
123: All notes off