hmm, interesting and something Im going to seek clarification on 
my understanding was, the routing of signals is fixed on the mSSP (so thats the patch?!)
but it says you can develop your own VSTs to load in, so I assumed you could drop different VSTs into the patch.
but its a good point to clarify…
I get the feeling this is not because percussa wants you to have to own a SSP as well , rather the UI for the routing would be difficult to port to such a small screen.
hopefully if this is the case, some ‘compromise’ can be found?
but, Im off to percussa forum to find out 
EDIT: ok, so i kind of got a response…
it seems we are both right… so the patches can only be developed on the SSP , however the VST “patch” will allow you to swap VSTs. how much flexility there is in that VST patch is not clear to me.
(and of course Id also need to see the performance of the VST under the mSSP)
in theory for my use this might be ok…
Ive already checked with percussa the hardware is pretty open, so you can pretty much run what you like on it… or put another way , these patches are ‘one app’, you can put on your own or you can integrate via a VST.
the only thing that worries me a bit, is it not open source,though percussa are helpful.
also for non-developers, I cannot see them being happy with the idea that ‘others’ are going to create patches for them… when the underlying hardware they have could do this too…
(e.g. imagine a web-app or something to design patches with?!)