Personally, I want to keep the idol. The dream cult was a huge, important, and long-running party of the culture here. We know that duchess Cai regards us as evidence of the spirits she defeated bowing to her dominion, out at least she has *publicly speculated* to that end, and I think that means we need to understand what she views us as representing. There's too much history here to just pave over and hope for the best.
And as far as the disruption of the spiritual ecosystem- I'm on the hedonistic "consequences are inevitable" side of the balance, rather than the "don't touch anything" side. We are not going to grow our cultivation without making a mark on the world.
And personally? I like the idea that we are becoming our lady leige's dark shadow. Where she is light and revelation and the truth of day, we are the comfort of night and dreams and actions taken in private. Both are needed for people to flourish.
Which means that dreams are key- what might be, and what is not- to give relief from the pressure of what *is* and being locked into a position in life where dreams are the only escape.
I don't want to throw that away to make nobles happier with us- they'll be happier that we are neutering ourselves more than they'll be happy that the past is being left in the past.