Looking for a monitor but not like most use - long read

I'm completely new to filmmaking and that's obviously going to show. But please take it easy on me for a while. I have a BMPCC 4K, and I'm working on a short film series in a specific location. I need am doing EVERYTHING solo, including the acting. So, while acting I need to be able to keep an eye on my framing, focus, audio levels, etc. I don't need color accuracy. I know most guys will throw an atmos ninja on there and call it good. But I don't need the external recording and, more importantly, the camera will be too far away for me to see such a small screen. Even a 7 inch screen will be impossible for me to tell if I'm in focus. I need something off camera. I'm also, and there's nothing I can do about this, I need the lowest cost solution. I know this is NOT a cheap lifestyle, but I'm doing what I can.
So far, I've tried an Asus VE22 computer monitor and an ACER PM161q portable monitor(LOVED the form factor) both of them wouldn't work with frame rates lower than 50fps. I could get away with something small like my cell phone if I could have it right near me and then hide it during the shot, but as far as I know there is no android app that allows monitoring of the BMPCC 4K. Shame, because it would be wildly practical for my needs, and that ACER would have been perfect for this project. But not at the expense of having to shoot at 50 fps. Other than shooting at a higher frame rate, what's my cheapest option here? Thanks everyone :]