it would be really cool to have an arpeggio input device, working with both vstis and samples… it could use the base notes you enter and after that just continue playing until it’s stopped (with capslock-noteoff or so).
A workaround to for this - to use hosts like Massiva EnergyXT VSTi.
It has internal arpegiator and many other useful abilities.
well sure, there are several vstis with that capability. that means, though, that i have to use just that vsti with the arpeggiator, and that’s way too limiting for my taste 
No! The goal of Massiva Energy is:
“energyXT is a modular MIDI/audio environment VST plug-in and
standalone that can host VST plug-ins itself. It’s main goal
is to enable flexible MIDI/audio networks of VST instruments
and effects, but the fun starts when you load up internal
components like the arpeggiator, MIDI envelope and the chord
component into the MIDI chain. The master output can be
recorded live and saved to wav.”
So it can host any of your VSTi’s internally !
i think a x-tra arpeggiator is an idea from a really lazy tracker user. why we editing music step by step in patterns!!! … is it so hard to copy and paste 3 or 4 notes, transposing the notes and so on … ?! 
i think an one-key chord creation feature is more important … for me as an lazy tracker user 
yea, i wanna see how you do that live.
besides, much innovation in modern software is not really needed, but is there to make things faster, and that’s more than just pure lazyness.
And even if you don’t use arpeggiator in the final song it can be a good source of inspiration when just playing around on your keyboard…
This should be not hard to create… make a chord you like, copy the chord block and then insert / paste the chord using the base-note you hit at that moment…
It’s just using the relative notescheme that is the most work.
But hey… i’m not a renoise programmer 
Isn’t is as always that finding a good user interface and concept is the most work? or… ehh… maybe you were talking about creating it in a pattern? 