Is it possible to add a button to the New Leads flow? Once a lead is created, I'd like to have the option to click save and create a new task. "Save & New Task".
There's a really old Idea for this you can vote on. For now, the basic answer is "no, you can't just add a button on this page." You could choose to create a custom component and use lightning:recordEditForm, provide a Button Override for the New Lead button, and then provide custom buttons do to what you're trying to do. It's not "impossible", but the workaround is relatively cumbersome. You might just want to create a component that you can drop on to the Lead Detail page to automatically pop up an Add Task modal or other technique after the lead is created.