These are the pictures of the different versions:
V1
V2
V3
It shows that there is no static design of the instrument, which I like.
I found snippets of information on the different versions in forums etc. There is not really one central point alas. Also watching and listening to this video of Rob Hordijk explaining and playing with the V3 Blippoo was very informative. Around 3’00" he explaines the S&H as well.
Hope this helps!