What threw me is that the video states that the symphony-cycle is a choral work, and I did not detect any chorus. Listening again closely, I think there is some vocal component to it, e.g. after 1:15 in the original video, but the chorus is very subdued and largely drowned out by the lower strings. So "four symphonies in ten movements" is about right, and my attempt to split the mp4 into individual symphonies as mp3 files may actually be correct after all. So I have left them.
Edit: I have found another performance of Symphony No 11 (only) which confirms the timing to be around 35 mins.
The music is quite good, but I guess only Karamanov or his offspring can clear it up with any certainty.