Some of my bank accounts have been switched to Mx while others are still under Mr due to the credit card company being a touch slower. I've also changed my medical records to Mx and despite the records with my employer being flagged Mr (due to their heel dragging with equality issues - I am planning to bring this up at my next meeting) and I've not had any issues at all as of yet. I also use Ms from time to time depending on how able I am to stomach the horrible dysphoria that comes with using Mr. Even just writing it just now is pretty icky.
For identification I use my driver's licence and it doesn't have a title but I've heard of some people using an Mx title on such without any issues. I guess it is just seen in a similar way to an academic title such as Dr - there will be times it can be used and times it can't.
By the way! Any title of Mr, Miss, Ms or Mx can be used without issue so long as you do not mean to defraud someone by doing so.
Up until now most people have avoided pronouncing the title when addressing me once they see either of these identifiers but the feeling is absolutely lovely when you get someone that is aware and refers to you as Mx!
