Hi,
I have read your requirements, I am an experienced shopify developer and I can help you fix the issues with metafields on cart page and checkout page.
I am ready to start work right now.
Over 6yrs knowledge and experience gained working in Shopify/Shopify Apps/Bootstrap/Responsive/CSS3/HTML5/jQuery.
Feel free to contact me anytime, quality work is guaranteed.
Best regards,
Wilson.