Personally, I embrace the fact that each string on a bass can have a distinct character. Compared to other stringed instruments, there is a wild difference in diameter between the strings, so it's just inevitable that the strings are going to have different tone, sustain, response, etc. I tune in fifths, so the difference is even more pronounced on my instruments.
In the DB world it is very common to mix sets because we are actually looking for significantly different character between the high strings and the low string(s). It gives the instrument versatility.
I suggest not to get too hung up on evenness of tone, and just accept that it is the nature of the instrument that each string is going to have its own character, strengths and weaknesses. Your fingers ultimately have to do most of the work in evening things out, when the music calls for it.
In the DB world it is very common to mix sets because we are actually looking for significantly different character between the high strings and the low string(s). It gives the instrument versatility.
I suggest not to get too hung up on evenness of tone, and just accept that it is the nature of the instrument that each string is going to have its own character, strengths and weaknesses. Your fingers ultimately have to do most of the work in evening things out, when the music calls for it.