Can you clarify this idea further, please? UpdraftPlus already has the capability to exclude named folders – https://updraftplus.com/faqs/how-can-i-exclude-particular-filesdirectories-from-the-backup/ – and there are also incremental backups if you don’t want to backup rarely-changing files each time – https://updraftplus.com/tell-me-more-about-incremental-backups/ .
David