On a slate 7 pro, turning of routing traffic via a tailscale exit node doesn't turn it off. It looks like it worked in the ui but the exit node is still used. This script actually disables traffic from being routed through the exit node for me
#!/bin/sh
uci -q delete tailscale.settings.exit_node_ip
uci commit tailscale
tailscale set --exit-node=
/etc/init.d/tailscale restart
sleep 2
tailscale status | grep -E 'active|exit node' || echo "no active exit node"
When tailscale is running and an exit node is used to route traffic, then in the UI I turn off routing traffic via the exit node (but tailscale is still being used), traffic continues to be routed via the exit node (confirmed with tailscale status).
Are you setting the BE10000 itself as the exit node?
Or are you simply enabling a Custom Exit Node on the BE10000 and setting other devices as exit nodes?
If I set BE10000 itself as an exit node, when I disable tailscale in the GUI, executing tailscale status only shows a message indicating that tailscale is not running.