chore (refactor): simplified Initialization and Reduced Redundancy

[hexcow]

I've made a few improvements to the code that streamline its structure while preserving its original functionality.

Key changes:

• Reduced duplication by simplifying the PoolBuilderConfigOverrides and reusing values where possible (e.g., backoff_time and pool limits).
• Improved readability by replacing repetitive Default::default() calls and directly using variables where appropriate.
• Simplified structure initialization by removing unnecessary intermediate variables and by reusing functions like Self::components(&self.args).

The logic remains unchanged, but the code is now cleaner, more efficient, and easier to maintain.