I’m proud to have been a big part of the development behind the Leaky2 plugin. Probably the best and most unique plugin that I been involved with to date. Leaky2 will let you leak part of the spectrum between L, R, Sum or Difference: https://www.noisebud.se/?download=leaky-1-0

, Noisebud Leaky2, Saintpid Mastering