From OP SDK i got this class : static OSArgument makeBoolArgument (const std::string &name, bool required=true, bool modelDependent=false)

if k == 0
 schedule_add = OpenStudio::Ruleset::OSArgument::makeBoolArgument('@add_sched',false)
 schedule_add.setDisplayName("Check if you want to create new and use as default supply auto fan schedule")
 schedule_add.setDefaultValue(false)
 args << schedule_add
else
 schedule_add = OpenStudio::Ruleset::OSArgument::makeBoolArgument('@add_sched',false)
 schedule_add.setDisplayName("Don't check because schedule has been created")
 schedule_add.setValue(false)
 args << schedule_add
end

From OP SDK i got this class : static OSArgument makeBoolArgument (const std::string &name, bool required=true, bool modelDependent=false) 1/I have question about modelDependent Which case we often use this attribute ? and How to use ? 2/ Have anyway to set value of argument without shown selection optional:

if k == 0
schedule_add = OpenStudio::Ruleset::OSArgument::makeBoolArgument('@add_sched',false)
schedule_add.setDisplayName("Check if you want to create new and use as default supply auto fan schedule")
schedule_add.setDefaultValue(false)
args << schedule_add
else
schedule_add = OpenStudio::Ruleset::OSArgument::makeBoolArgument('@add_sched',false)
schedule_add.setDisplayName("Don't check because schedule has been created")
schedule_add.setValue(false)
args << schedule_add
end

In my case , dont want to show check box if k differ than 0 - hardsize as false.0.