1. To customize ~/.tabby/config.toml in the Modal installation guide, you can follow the steps outlined in the Tabby documentation for configuration. Here is a general guide:

# Update the ~/.tabby/config.toml file
# Add your custom configurations

2. To declare TABBY_DISABLE_USAGE_COLLECTION=1 as an environment variable, you can do the following:

export TABBY_DISABLE_USAGE_COLLECTION=1

3. For using the Tabby command line in a modal use case installation, ensure that you have the necessary configurations set in the ~/.tabby/config.toml file as per the Repository context for code completion. Refer to the Tabby documentation for detailed instructions on setting up the configuration for code completion in a modal installation.