Hello Nick,
We already release the update on 2 October 2021 and you already got an email for the update. Please download and use the updated plugin.
Moreover, we are sorry to say that there is no easiest way to make the font bigger on the invoices. If you need a customization service based on your specific needs and requirements then please send a message using our Envato Market (codecanyon) profile contact form to click here https://codecanyon.net/user/themelooks#contact (screenshot as reference https://prnt.sc/10o0iwt ) with your requirements with details to get a quote.
Best Regards,
ThemeLooks Support Team