I went through a similar firearm event 3 years ago. There was a clear difference between right (damaged) and left ear. Did the prednisone drill without any obvious improvement. I had Philips 9030 HA’s fitted which worked pretty well. My Costco audiogram as well as some online tests showed the clear difference in ears. Last fall when the 9050’s came out I had another audiogram that showed a reduction in the differences between ears. The 9050’s worked very well for me.
Bottom line - you may see some improvement over time from having a quick prednisone treatment. I am not a doc. but I have no other explanation for my situation. As they say, YMMV.