I have seen those and they did look interesting but I came to a different conclusion, Headless SKR Pro Info - #84 by vicious1. The ESP-01s is pretty rad, The worst part is if you do want to do file transfers they are very slow. The rest you have full control wirelessly. You can see in that thread we kinda messed around with it for a while.
Your card issues could be all sorts of things. Some brands just do not work well, fat vs fat32, folder in the root. Super new fancy cards typically do not work well, but it could just be the adapter seems a bit wonky vs the esp-01, but having the card port is nice.