So I have my Blackfin and no 3.57 or lower Vita. I tried with multiple PSTV's and it doesn't work for any of them. I am not the only one either as my friends have tried but alas do not work. What's even crappier is my rear touch pad has stopped workin on my beloved Vita so I need one for latest firmware and one on 3.57 or lower to test this out for PSX-Place. Also the Vita slims can not shut the card door with the Blackfin card inserted. This is all for now but I can attest to the P2P server...
Confirmed, Blackfin does NOT work with PSTV
Confirmed, Blackfin does NOT work with PSTV
