I really love the ideas you have going here, and the development of the choir was really cool, I think the nature of the repeated chord structure is fine but I will echo what twitchey said and encourage you to try adding a bit more happening in between the lines to help develop it more, running string lines or piano countermelodies, I actually think a good example of this is Lusamines Final Theme in pokemon sun and moon, as well as Insaneintherains interpretation of it, specifically the part around 1:15, but overall his piano parts are very good at staying active and I think you could apply that to writing for strings in more shot heavy works as well. Good stuff though, this was a super enjoyable listen to me.