I think it should be allowed. It is not a game breaking thing and will not happen often enough to plan around it. I see no issues with this personally.
I have played around with it as well but saving the orb until Eva has been to difficult for me to do consistently. I think there is to much rng involved to try and bank on that as your strategy because its spawn rate is so low. I still buy it whenever I can though.
I had the knife bound for a while in my runs but did not have good luck with it, but ill chalk that up to poor rng on my part. I did have a run with +50 gold going into the first peculiar room.
I am all for making a glitched run category. I will make one right away and please feel free to submit your run again. I felt the rules were not very clear in the original description as to where to properly start and stop the runs. I also want to make a burrito mode category