When I got divorced many years ago, I had asked a posek how to spell Mendel, with or without an eyin, and he looked in a sefer and said with the eyin.
My question is, is this an obligation that I must always spell it that way, or I can now choose to spell it without the eyin, which is the general way that most people spell it?
I do not spell it with a yud, and that Rov didn’t ask me.
When you write your name it doesn’t really matter how you spell it, as it has no real halachic ramifications. When you get remarried, you would however want to tell the mesader kedushin about it to see if it will make a difference or not.