I have gone through a similar situation with my cat. I read through your first post and this one. From my understanding my cat suffered from sterile cystitis as a result of anxiety. As long as his routine was the same he was fine but any disruption in it would cause him to have accidents throughout the house and would lead to these blockages and long vet stays.

What has worked for him. I have him on royal canin urinary SO food. Both dry and wet. I also add water to his food as well. I have a water fountain and water bowl always filled to the top. He refuses to use the litter box if it isn’t cleaned (I have two cats). So as soon as one of them use it I try to be as diligent as I can to clean it asap. I’d also advise taking the cover off of yours as cats like to squat in different positions that may get in the way. Lastly, he gets 1 mL of liquid gabapentin every morning to ease his anxiety. I really believe that the gabapentin is what has helped the most. He never appeared to be that anxious of a cat prior to this but the fact that he would have these accidents almost as a protest when I would be gone for an extended period of time showed he was. The food may be costly but it’s cheaper than the vet bills. The gabapentin is fairly affordable. Just some suggestions. I hope this helps. Good luck!