Microsoft
MicrosoftHi mrBrnm , that is a great question.
Please take a look of this:
When the receiving client fails to process a message but wants the message to be redelivered, it can explicitly ask for the message to be released and unlocked instantly by calling the Abandon API for the message or it can do nothing and let the lock elapse.
In addition....
If a receiving client fails to process a message and knows that redelivering the message and retrying the operation won't help, it can reject the message, which moves it into the dead-letter queue by calling the DeadLetter API on the message, which also allows setting a custom property including a reason code that can be retrieved with the message from the dead-letter queue.
More details Azure Service Bus message transfers, locks, and settlement - Azure Service Bus | Microsoft Learn
Regarding the cache capacity, due this is an app setting configuration, it will affect all workflows in the logic app (Standard). Please refer to Edit runtime and environment settings for Standard logic apps - Azure Logic Apps | Microsoft Learn for more details.