I don't understand people that ask questions for which they seemingly have all the answers.
If you want a job doing tree work, and you obviously have some credentials that would lend themselves to the benefit of a company, then GO GET A JOB. Go to work, perhaps your expectations are too high.
I for one, would only be happy to see your CDL license, the rest tells me you've been educated just enough to make you think you know whats going on when it comes to arboriculture. When in reality, you DON'T.
It bugs the everloving @!#@ outta me that someone with >3 years of landscape experience and a degree in horticulture can challenge the ISA cert without a problem when they, like you have admitted, know nothing of everyday arboricultural field operations. They are now landscapers that have 'tickets' to do treework. It needs to be a red seal trade, like a carpenter, or even a line clearance arborist. BC, where I live has recently taken that step. I believe that the ISA cert is devalued because of this phenomena.
It tells people with the requisite experience and demonstration of knowledge, people like me, who have earned the certification through blood, sweat and tears as an apprentice to a journeymen working in the field for the requisite time, it tells us that someone who mows lawns for 3 years can claim to do what we can. That they might flash their ISA to a potential customer and be taken as seriously as us who have ACTUAL experience and knowledge is a serious problem to me.
Furthermore you have explained that you plan to challenge a certification you admit to not having requisite experience to hold...ridiculous. Take a casual course in a local college, prune a few trees on a landscape crew and all of a sudden you're an arborist, eh?
You live in a large market, and you can't find an interview? Have you exhausted ALL possibilities?
The best way to get an interview is to get an interview. If you can't figure this out, then find another line of work.
Be resourceful, be unorthodox, distinguish yourself from others. And above all, BE HUMBLE. From your responses here, I would wager that the way in which you speak to potential interviewers on the phone or in person may make them see a red flag. The biggest sore spot when it comes to training anyone, in any trade, is when the trainee thinks they know what they are doing and the journeyman KNOWS that the trainee hasn't a clue.
To add; if you can't find an entry level position in tree work, you won't be able to find a job anywhere. I think its just you, not potential employers, that has the problem.
Pack brush, chip brush; repeat. Show some initiative, show some work ethic; and your boss MAY decide that you are a candidate to progress. But thats up to YOU!