Why I'm writing first-person present tense for main character, and third-person present tense for other characters. Tell me your opinions or tangents!

So my novel takes place in an afterlife and focuses on one major character, as they try to heal from childhood trauma, learn helpful mental health tools, and newly take in this beautiful universe.

The other major characters are also developing ethically and emotionally, and we need to see inside their minds and watch them learn.

Meanwhile the past was literally a different life, and there's not a lot of past talked about in the narration— more thought about or talked about by the characters.

So with that, I've decided that the best way to write my novel is first-person present tense with the main character; and then with the occasional times where I need to focus on other characters when the main isn't around, third-person present tense.

This is not a common choice, but I think it is the best choice for my particular novel. I think it's the best choice for my novel's sense of immediacy, for getting inside characters' heads, and for experiencing many new things from the main character's viewpoint.

Also also, I intend to make my main character Chris/Solemn completely-ambiguous when it comes to gender; so that really works with the first-person perspective.

Tell me your opinions or tangents!