Hi,
I am sorry I don't have much to share on this med, except that hydroxyurea is also on Dr Afrin's MCAS radar as well.  When I was confirmed as having MCAS, he included a list of potential meds to try in my office note.  There are literally dozens of meds on here, but this is what he says about hydroxyurea.  

...More expensive and/or potentially more toxic agents include hydroxyurea (typically starting at 200-500 mg/d and escalating monthly as tolerated follow blood counts weekly in the first month, monthly in the fist quarter, and 2-3 months thereafter)...

My best wishes in getting your trypatase lowered.  
Lyn

Do you know why they aren't considering Midostaurin?

My understanding is that Gleevec works best on people who do NOT have the C-kit 816V mutation.  You might not qualify for the Midostaurin clinical trial, or you may have reservations about being in a clinical trial at this point.  The criteria are very specific.  There is information about it online.

You must be lucky or doing something right to have your mutation go away.  That must be very rare.

I don't know if it makes sense or not, because I'm not a doctor.  I'm also not advocating one way or another.  However, I can see that you're not comfortable with what you're being told.  That's very important and not something to ignore.  

IMHO, chemotherapy is a big step, and if I weren't 100% certain, and if it weren't an emergency to start on it, I would keep researching and seeking out other opinions until I was sure.  I asked my allergist which specialist to see, and he told me that if I get an opinion and it doesn't feel right to me, then I see another doctor, and then another...and another, if necessary, until I feel very comfortable with what's being proposed for a diagnosis and treatment.  Now that's assuming I wouldn't be closed minded about considering what's being suggested because of fear or some other factor.

You might not get them, but there are some potential side effects from hydroxyurea.  If you haven't, I would read up on it so you know what this option would mean.

I think the determining factor in prescribing chemo is how much damage the mast cells and mediators are doing/have done in your body, and what is showing up on physical exam, radiological testing, and blood tests.

Have you thought about asking Dr. Gotlib his opinion?  Since you've seen him before (I think you have), he might be willing to look over your records between then and now and give you his recommendation.  Or, you can always go for an appointment there.

So, I would say to follow your instincts and get more opinions until you feel comfortable with whatever treatment you decide you should do, if any.  Good Luck, Bob, with whatever you decide.  If you do get more opinions and feel like posting, this is relevant to a lot of people on this forum.