With the past version of the launcher, I was able to bind my Logitech mouse's settings to Minecraft.app, in order to change the functions of the buttons to more game-specific ones. However, due to the launching technique used in the new Launcher, this is no longer possible.

I believe that applying a bundle ID of "com.Mojang Specifications.Minecraft.Minecraft" to the launched instance would fix this, since it would appear to the system as though the game were the same app as the launcher, but I'm not sure if this is possible. The other option would be to generate an application bundle with the proper ID, then launch that.

Note: I completely understand if you don't want to worry about this, since it's not really an issue with the Launcher on its own, just thought that I'd bring it to your attention. Being able to modify my mouse configuration automatically while playing greatly improves the Minecraft experience, and I'm sure I'm not the only one who uses this sort of setup.