Slack With Your Agency Clients

Anybody at agencies forced to use Slack for client communications?

An agency I’m freelancing with is making me do this and I’m terrified that it will provide an expectation of always being available. I love Slack for internal communication, but would prefer to use email and/or Zoom with the client. Even a task management tool like Asana would be fine. The Slack instance is unpaid too, which means records/approvals/etc. can get lost after a few weeks.

I literally only have ~3-5 hours per week to work on this account and don’t want it taken up chit-chatting over Slack. Has anybody used Slack with their clients and had a positive result? Is this basically the new standard that I need to adapt to?