Why dont you use the built-in arpegiator?
Works well for me
Afaic see BlueArp should be used as a FX-plugin, since the VST has no OSC, it can not make sounds on its own. I have tried with several of LMMS instruments, and presets. BlueArp does recognize LMMS-input. The transport dots starts when a key is pressed, and stop as soon as the last reverb on the note is gone, but there are no arpeggio output.