The single widget reload functionality was an experimental feature that was conditionally enabled to prototype faster hot reloads. Experimental data from beta branches/g3 showed no improvement/regression in performance for the change, so it was never rolled out. Nevertheless, there are still a few pieces of code that need to be cleaned up.

• remove the Widgetcache and associated cmd line flags from the front_end and frontend_server packages:
• Remove the DebugReassembleConfig class from the framework
• Remove the singleWidgetReload feature flag and associated code from the flutter tool.

The only caveat is that the dart SDK should be updated last.