If I may give my point of view in this matter as a PBK...
Originally, the Murlis were of around 6 dense pages, without essence, questions, answers, then afterwards essence for dharna, then blessing, and finally slogan. So if you take out all this stuff, that was not there originally, and is a addition made by human beings and not ShivBaba (except the blessing but it was not part of the Murli), what is left? a squeleton, a ghost of what it was.
So what about what was originally there? It has been taken out by human beings, and not ShivBaba, otherwise he would not have spoken it first place. For which purpose?... the human introduction to the Murli is there to lead our understanding of the Murli. the conclusion is to insist on what we should take from that Murli. Why then does Baba tell us that Gyan is important, and we should churn it? Why do they think they are entitled to direct our thoughts? Or do they have anything to hide?
Now if I may give the PBK version, as simply as possible, even if this does not fit in your vision of the reality, just take it as another story:
There is then a whole period when the "Murlis" called then the Peo's Vanis, or Piu's Vanis, are said by the Chariot Sevakram. Other important personages are involved in this story, but I have to cut the story short. I maybe can expand in the PBK department.
When Dada Lekhraj got his visions, no one could explain them to him. The last person he thought of was his business partner called Sevakram, someone who was so reliable that he gave him half of his benefits in exchange of which he would do all the work. At that time, in a very specific way, I simplify, Shiv entered that person to explain the visions. This seems more realistic than the official version, where after searching, Lekhraj Kirpalani suddently have Shiv in him uttering "I am Shiv" etc. , what would have been enough to make him at once understand the meaning of his visions.
From 36 to 51, when the Sevakram (41) and his group have all gone, the official Murlis start, from 51 to 69, when Lekhraj Kirpalani leaves the body. those are the "18 chapters of the Gita". The one who I now consider as the new Chariot, Virendra Devi Dixit, gives the clarification of those Murlis, which started from 76. The BK authorities managed to get hold of those, and accordingly, to cut bits of the Murlis that could be too compromising to them. So I don't know which 5 years Murlis have been taken for study, but I do believe that any Murlis given by ShivBaba through the Chariot of Lekhraj Kirpalani are valid. Baba says that if this one (the Chariot) makes a mistake, then he takes the responsibility. Now it is the same for the new Chariot.
The problem comes from the fact that the children got attached to the Chariot (Lekhraj Kirpalani) and put aside God himself. If the attachment went to the knowledge, then the second Chariot would have been accepted. I think the BK authorities are genuine but they are blinded by their attachment. Why would God himself be dependant on one Chariot, and not able to continue his work in a practical way?
My opinion on the Avyakt Vanis, is that it is only Lekhraj Kirpalani alias Krishna who is teaching dharna, in remembrance of God. Not a single sentence he has said goes against the Murlis, it does match totally. He comes out of attachment for his children, and because he is called.
In the Murli of the 25.3.73 p4, Baba says "Whenever Father comes, does anyone come to know about it? No. One cannot even know." When it is through Dadi Gulzar, BapDada is called in advance, and then there is meditation, and then there is a jolt. This is really visible. But just to let you know that Krishna has a crucial role in this epic, he is in fact the protagonist (heroine) with Ram/Virendra (hero). He is still playing his part now in the Advance Party.
This is anyway what I think.