On/Off Parameter displays in CloudFormation template

This isn't possible; the list of Parameters in the Console is statically displayed.

You may be able to improve the user experience slightly with the AWS::CloudFormation::Interface metadata block, which lets you group parameter items and add explanatory labelling: https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-cloudformation-interface.html

Hi, while not possible natively in CloudFormation, you can use Cloud Development Kit (CDK) to have such parameters. Please see https://docs.aws.amazon.com/cdk/v2/guide/parameters.html#parameters_deploy