Describe the Feature
Sometimes the SetOption function should override the option the user set from the command line.

In our case we are trying to protect our users from shooting themselves in the foot when they use a large -j and forget they are not using icecream (distcc like tool). Icecream handles the large j by queueing things up, but if you forget to enable icecream on the command line your system gets hung, and generally our devs need to reboot

Required information

• Link to SCons Users thread discussing your issue.
  https://discord.com/channels/571796279483564041/571796280146133047/836360074741022822
• Version of SCons
  mongodb vendored scons ~= 3.1.2
• Version of Python
  3.9 (with opts)
• Which python distribution if applicable (python.org, cygwin, anaconda, macports, brew,etc)
  N/A
• How you installed SCons
  local source
• What Platform are you on? (Linux/Windows and which version)
  Ubuntu 18
• How to reproduce your issue? Please include a small self contained reproducer. Likely a SConstruct should do for most issues.
  I'll add a repro when I have time
• How you invoke scons (The command line you're using "scons --flags some_arguments")
  N/A

Additional context
Add any other context or screenshots about the feature request here.