You've asked, we've heard!
The Quick SMS endpoint (v3/sms/send) now supports the ability to send shortened URL links, saving your characters for what matters most - your message.
For the moment, this is limited to API users only, but the dashboard experience will be coming out in the new year.
To find out more, please visit https://developers.clicksend.com/docs/messaging/sms/#operation/send-sms for guidance on integrating and https://help.clicksend.com/article/1cqf0m0vni-short-url-in-quick-sms for a more in depth explanation