Arpeggios are unreliable if you have an odd tempo. Note delays piss me off for the mere fact that it takes a while to type them in (I will if there's only a few triplets in the song), I'd rather simplify things and change the pattern speed/style for triplets.
I'd do a note delay... I dunno how you could do it with an arpeggio.
Oop, never mind... I figured out what you meant. I forgot that arpeggio envelopes don't necessarily have to loop (since I pretty much always loop them).
