Diagnosing or Ruling out Insulinoma

Fairly new to this forum as I navigate the slow process of diagnosing or definitively ruling out an Insulinoma. First visit with an endocrinologist last week believed my frequent episodes hypoglycemia (non-diabetic) is caused by a a combination of Zepbound/Mounjaro (that I had discontinued several weeks ago) and a pancreas that doesn’t function well with carbohydrates. They suggested I follow a low-glycemic/post-bariatric surgery diet and return in 4 weeks for a follow-up. I have never had bariatric surgery, not diabetic, do not abuse alcohol, discontinued Zepbound/Mounjaro (for weight loss), no exogenous insulin, etc. I lost 55 pounds over 2.5 years while on Mounjaro and am/was very fit until I started gaining weight in May. I will add I was on Mounjaro while starting to gain weight. I have had frequent/almost daily episodes of Hypoglycemia with 1 episode requiring an ER visit and 2 in the last week that were refractory and lasted over 10+ hours, going in and out of hypoglycemia with a resolution period anywhere from 45 minutes to 2+/- hours with 30g carbs each episode. It was the last “refractory” episode that prompted my endo to prescribe Baqsimi (glucagon nasal powder) which I have read in the insert is contraindicated if you have an Insulinoma. They would like to order a 72 hour fast but was required by insurance to order an 8-12 hour initial blood fasting test which I had today: glucose (value was 93 mg/dL), insulin (value 10 uIU/ml), and c-peptide (still waiting on). Worried insurance will not approve the hospital stay and what my next steps should be.
My questions are:
Are refractory episodes of Hypoglycemia a strong indication for an Insulinoma?
Has anyone with an Insulinoma been prescribed Baqsimi for emergency use?
How to find “best” Dr./hospital locally with experience with Insulinoma. I live in Denver, Colorado. Not opposed traveling to a Mayo Clinic for testing if warranted. Which location is best for diagnosing/treating Insulinoma?

Thanks for your help!