Radiant: Where can I set the set -exp nbrCongestionEffortLevel=5 command mentioned on the warning message?
-exp nbrCongestionEffortLevel=5 is a command line option of Place & Route Design.
You can type or copy this on the Command Line Option strategy setting of Place & Route (PAR) Design. Then click Apply followed by OK.
This will apply the PAR Explorer option (-exp) to optimize or modify PAR behavior.