I think you will benefit if you skim through this hyperlink - thread that talks about the process I actually went through to provide evidence to my VRC regarding my reasonings to transfer my employment as a senior pharm tech to going to pharmacy school:
Chapter 31 "Qualifying for Voc-Rehab" Journey
First though, to answer your question: do NOT put off med school. If for any reason you are found approved, they will back-track to the initial date of your application and pay you any past tuition, housing, & books that went to your education. You may even get granted a laptop and printer as well.
As for your case you do have options but its very limited. If you look up this link about
Determining employment handicap as put out in 38 CFR 21.51, it will outline determining factors in approving or disapproving an applicant. The 3 things to focus on that is mentioned is targeting your "abilities, aptitude(s), and interest(s)." Now, if you state that your disabilities do not hinder your ability for employment, you are at a dead end. The drive behind this program is not titled as an educational program, but rather a rehabilitation AND employment program. If you have no hinderance that requires a career change, it ultimately defeats the purpose of being granted VR&E benefits.
However, the argument you could attest is that overtime, your service connected disabilities may worsen over the short and long-term of your nursing career resulting in cut hours or low income to not support yourself and/or family. Thus, if you accomplish a secondary degree (ie medical school) while your health allows you do to so, this would grant you an opportunity to turn your now primary career in medicine as a fall-back career should your SCD's become aggravated over time. If your hours were to be cut as a physician, you'll still have a greater likelihood of generating enough income to cover your basic costs and not hinder your ability to take care of yourself and/or family. This was the exact approach I did (pharm tech vs pharmacist).
You have the choice to appeal or start fresh with a new VRC at the region you will be attending Medical School. I actually was denied twice in the state I was leaving my AD service and got approved in the state I am now attending school. What also helped me was providing an acceptance letter, my college transcripts, the actual copy of 38 CFR 21.51, and a copy of the
Occupational Outlook Handbook Bureau of Labor Statistics and provided job growth potential in multiple areas of the country with wages and educational qualification factors (through the Occupational Outlook website). This is half the battle, the other half is the mood of the VRC and how well you are prepared to answer questions based on evidence provided before-hand. Essentially, the easier you make their decision, the higher chance you have of getting accepted.
