doIf may help here https://gatling.io/docs/current/general/scenario/#doif
exec(http(…)).doIf(session => perhaps)(pause(5))
https://gatling.io/docs/current/general/simulation_setup/#global-pause-configuration
Different pause and pace overrides: https://gatling.io/docs/current/general/scenario/#pause https://gatling.io/docs/current/general/scenario/#pace