Another thing you might want to consider is creating all this in a template file you always use, so once you've gone to the trouble of creating it, the style is available to you.
Next, make your block but make sure it's NOT annotative. All the annotation happens in the Multileader style.
Second step, use the button in your Dashboard to start the Multileader Styler command.
Here you can see my preview, I chose my custom block, straight lines, annotative scale and all colors by layer.