The search block is currently very rough to use as a design element on a theme or navigation design. It currently renders like this:

This block should have some options in its attributes to:

• Not render a visible label. (@apeatling) Search Block: Add button, label, and width options #24666
• Allow rendering a magnifying glass icon and use it as the submit button. (@apeatling) Search Block: Add button, label, and width options #24666
• Allow not having the submit button visible. (@apeatling) Search Block: Add button, label, and width options #24666
• Control over border radii. (@apeatling) Search Block: Add support for setting the border radius #25203
• Control over background color [Search Block]: Add color support to search button #32416
• Control over text color [Search Block]: Add color support to search button #32416
• Control over border color. Search Block: Add border color support #31783
• Control over margin: Search: Add margin support #63547
• Control over typography: Search block: Add typography supports #43499
• Allow expanding the field on focus Search Block: add button only with expandable input #50487
• Ability to render search interface as a full-screen overlay (and other treatments).
• Control over padding: Tracking: Dimensions Design Tools Consistency #43243

Some of these could be built as variations offered when inserting the block (in the placeholder scope).