Actually, scripting app is available in all bases, and will remain available in all bases, even for bases in free workspaces. So go ahead and write your script in scripting app and call that script from a button field.
Scripting automations are a different matter–those are limited to pro workspaces and above.
You can actually use any data change to trigger an automation, not just a checkbox field. I prefer single-select fields to checkbox fields because they are less prone to accidental clicks.