Some Delivery Controller regkeys can be set for Cloud Connectors.
From Version 1.15 of my Citrix Cloud doc script:
# Added Functions ProcessControllerServiceConfig and OutputControllerServiceConfig
# Outputs data from Get-BrokerServiceConfigurationData
#
# There are 66 possible settings configurable by Set-BrokerServiceConfigurationData
#
# Since you have no access to set these registry keys and values on a Cloud Controller,
# use Set-BrokerServiceConfigurationData to configure the setting and value
#
# Set-BrokerServiceConfigurationData Core.MaxHeartbeatIntervalMs -SettingValue 360000
# Running this will set the MaxHeartbeatIntervalMs to 6 minutes