I, too am looking for confirmation ref serrapeptase and myelofibrosis. I took a nice product for a while which I found at a very good price (relatively). Now I have just contacted my medical herbalist because I have found the following comparisons with pure serrapeptase. It does sound as if it ought to be beneficial, doesn't it!

... here is one comparison:
http://www.serrapeptase.org/serrapeptase-reviews/best-systemic-enzyme/
and another brand:
https://astenzymes.com/serracor-nk-vs-neprinol-brand-comparison/
Confusing, don't you agree?

I took serrapeptase for a while believing it could possibly 'eat-up' the fibrin - logically it should. However, it was rather expensive and I had no evidence that it did do this. More recently I was advised on this site to take sprouted broccoli powder, but within the liposomal mixture I make, as it can be destroyed in the gut otherwise. I have just begun adding a tablespoon to the mixture: I use a jewellery cleaner (see liposomal vitamin C on youtube). First I soak 6 tablespoons of organic sunflower lecithin for four hours in two cups of water and then put it in the blender for a minute. I then put 3 tbls of sodium ascorbate (vit C), 1 tbls of curcumin and 1 tbls of broccoli powder in one and a half cups of water and add immediately to the blender for another minute. I then pour the whole mixture into the jewellery cleaner for 22 minutes (this time recommended by a doctor who also makes her own) and pour into a jar to put in the fridge. I mix half a glass of the mixture with half a glass of vegetable juice and take regularly (not all in one go!!) with other supplements.
I should say that this practice, plus the other supplements I take, has brought my PSA figures down from 15.5 to 7.7. The nurse was astonished - she asked what I had done to achieve this and took down the list of supplements! (I take no medications except Anadin Extra every 24 hours for a nerve trapped in my back.)

I took serrapeptase for some time. It needs to be coated. All the same, I had no evidence of any improvement. Onamission recommended putting Broccoli sprout powder in the liposomal vitamin C mixture (+ curcumin) which I make. He then recommended adding Quercetin which could also otherwise get destroyed in the gut. I was just about to add that this morning when I came across this article by Dr Mercola demonstrating how vitamin C and Quercetin are a good combination against COVID 19!
https://articles.mercola.com/sites/articles/archive/2020/08/24/quercetin-and-vitamin-c-synergistic-effect.aspx#commentfocus
Incidentally, I was diagnosed in 2010 with Primary MF, have taken no medication at all and was recently told to carry on with what I am doing by my consultant as I am unusually stable. I do consult a medical herbalist and take a selection of supplements, organic food and more and more sunshine!
Good luck