Community feedback suggests a clear divide in how Beta 11 is utilized:
If you are currently running an older version of TuffClient, upgrading to Beta 11 is highly recommended to take advantage of improved block mapping, better performance, and superior 1.21 item support. To help you get the most out of this, let me know: Are you having trouble or finding the client? Do you need help configuring the 1.21 texture pack ?
Keep background browser tabs closed while running Beta 11. Chrome and Edge throttle background performance, which can choke active WebAssembly allocations.