I am surprised that those rockets are still consuming your mind after Ivanov's statement. He didn't have them in mind. He was pursuing a different lead.
Obviously, we have very different readings of the Ivanov's 1990 article. At the end of the article he delivers two very strict messages:
- cause of the DPI was appearanсe of fireball(s) on the spot;
- fireballs could have been piloted by "astronauts", in other words, people could have been inside.
This leaves us very little space for constructing theories.
There are also two interesting unofficial pointers to a rocket's involvement. In private chat, Dr.Vozrozhdenniy revealed in 1983 that Ivanov actually found out that it was a failed rocket test and even suspected particular launch site. Also, at the end of communist era of the Soviet Union, Mr. Romanov , a new secretary of Sverdlovsk Obcom (where Kirilenko used to be the 1st secretary) was curious to know what had happened with the Dyatlov group. He was told by his experienced colleagues that the hikers had become victims of rockets tests. As I tend to listen to all sources, not only case files, I take it seriously.