IX split is not in the target machine's list, all gens are in the list, but only midi gens works, of course with Polac's vst, it works for all synths.
Same thing with with mC1, not in Arpeggiator's list, is it definitive?
edit
Solved, with Polac's internal midi and send option, IX split and CyanPhase mC1 works like a charm with Jeskola Arpeggiator
On my computer, split plays notes around 80ms before mC1, but with a delay we get synchro, cool, split + arpeggiator is great.