Brf....stated my thoughts. Just reverse mod it for resale.
I mod just about every item I have for sonic improvements, to include amps, sources and speakers. What I want from a component is more important than what the next person may want. I would never listen to a component that I wasn't happy with or didn't feel that I could improve on.
And, when it has come time to sell the item I have always received more or, at least, the same price an non-modded unit would go for.
There are many reasonably priced electronics that benefit from mods.....from vintage tube amps through speakers. Most people I know would rather pay for a great sounding modded unit than a bad sounding stock unit.
So, IMO....go for it. Why limit your enjoyment. It sounds like you enjoy music at concert volume levels and, as you described, this piece, stock, does not perform and introduces distortions, that you have become sensitive to. Once you notice the distortion it will always bother you.
If you really don't want to mod them, for fear of your "investment" then sell them and buy something that meets your sonic needs.