Hi @GuerosUnderhood ,
Welcome to the community 
Can I increase it on get-side or get the link indefinitely?
The expiry is set from the product end and it can’t be customised as it’s an intended param set.
Here’s another relevant thread confirming the expiry set - Need clarification of conversation attachments
But, everytime you try to fetch ticket/coversation detail you should get the attachments payload and it should be accessible I hope. You can hit the API/use our SDK client.data.get("ticket") and utilise it on your end right?
Since, I’m not sure of what you’re trying to achieve shared the generic suggestions. Let me know some details on your usecase in case if you expecting extended clarifications on the same.
Thanks