What will happen if I run your script with option to split to 4GB chunks against a folder containing large files >4GB and files <4GB? Will it fail on 'small' files and continue splitting large ones? Let's say that I have following folder structure:

/data/files/x/
/data/files/y/
/data/files/

all of them contains files from 300MB to 100GB big. Ideally I'd like to run script in tmux/screen session and check once a day.