Interesting ideas.
I have a weird mind.
The SDA and Jews for Jesus type groups are the only “reasonable” nexuses there are between Jewish and Christian practice today, and SDA kind of stumbled into it and does not have as well developed theology here. I’ve seen some “unreasonable” ones that misunderestimate the role of Christ, but not talking more about that here.
I don’t go for supersessionary theories here as far as a literal Jewish people is concerned. That is a line of Abrahamic faith whose recognition of a Savior is to come in the future and will at that time crown the faith story of the world once more, bringing both Old and New Testaments to fulfillment.