The lateral transfer and redesignation board process is not a guaranteed thing, even if you are a stellar performer. The needs of the Navy govern all. Once or twice a year these boards convene. Eligibility is established, as in you usually have to have earned your warfare pin in your current community and be in certain year groups, not too junior, not too senior. Anyone transferring into a new community must be viable, career-wise, in their YG, and not have to spend time catching up. Your YG is roughly your commissioning year cohort.
You submit a package with documentation meeting the CEC desired criteria and a cover letter to the board, and it will have the endorsement of your current CO. Of critical importance, the manning levels in your community and year group must be sufficient to be able to release you AND the receiving community must have room for you in that YG AND stellar performance is a given AND your CO’s forwarding endorsement must be exceptionally strong. There is a big difference between “Forwarded, recommending approval” and “Forwarded, with my strongest personal and professional recommendation. LTJG Last Minute is my top-performing junior officer of 15 assigned, expert on the systems he oversees, unusually STEM-smart and a proficient, well-respected leader of people. Though I would be sorry to see an officer of his potential leave Surface Warfare, I believe he would quickly adapt to the CEC community and become an equally top-performing asset there.”
As for trying to go Restricted Line or Staff Corps out of NROTC, unless there is a specific provision for it, that’s not the mission. Rarely, if a midshipman is NPQ for URL, I think they might be allowed to go elsewhere than URL.
I’ll defer to our resident PNS
@GWU PNS to comment more authoritatively.