You have other big things on the SSD you run MSFS on ? I haven’t tested the below, @TenPatrol came up with a tip recently, when I look in my installed directory root (two levels above Community), I see a UserCfg.opt file.
When I open that file, the last line refers to the \Packages subdirectory. Maybe you could change the setting and move the whole \Packages branch to another place ? Official and Community… here the line sais
InstalledPackagesPath "C:\Users\user1\AppData\Local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\LocalCache\Packages"
In combination, you could use the link method Sven suggested, you may be able to point certain things back to your other SSD ? and balance things out better ?