Safari app extension development workflow

I write the code and want to see results as fast as possible.

Currently i am working on safaro extension with lot of javascript files and i want to see how websites react to it

Previously my workflow for safari app extension looked like this:

1. Write the code the code
2. build safari extension target
3. reload the page

After some xcode update, it did not work.

I realized i needed to do the same but with Application target(small difference).

The next day after upgrading to macOS High Sierra this does not work either.

Now you need to:

1. build the application target
2. open Safari preferences
3. remove and add checkbox near your extension
4. close preferences,
5. reload the page and wolla!

Guys, is this intended ? Or there are other ways to do this ?

UPDATE. I already automated this using applescript, but still want best practice for safari app extension development workflow.

Thanks