Not the same thing or what I replied about. This was about loading Ir's and having the impedence curve for it load.The curves have nothing to do with the the ir though. The pre v11 curves were defauted by amp. You could change the ir to whatever you wanted and the default curve didn't change.
The solution is, before you make any changes to your existing preset just copy the amp channel to another channel, then change it on one channel and compare the two channels to see the difference.