Drawing from my extensive 6+ years of hands-on experience as a full stack developer, I possess the necessary skill set to carry out the required modifications to your Chrome extension. I specialize in JavaScript and have in-depth knowledge of Angular, React, Vue.js and Redux just to mention a few. These skills are crucial in working with Chrome extensions like yours and ensuring efficient data scraping.
As you mentioned wanting to sell your extension on a monthly subscription basis, I can leverage my proficiency in NodeJS and SQL (specifically MySQL) allowing me to restructure your extension for better maintained user subscriptions. On top of this, I'm an expert in compile tools such as Webpack which will surely facilitate smooth operation once the required modifications are made.
Lastly, but perhaps most importantly, my commitment to client satisfaction is second to none. I assure you that I will work diligently and communicate thoroughly throughout the project until we both consider it successfully completed. Thank you for considering me, and I look forward to contributing my skills towards making your vision a reality within your budget constraints.