KOreader and Coolreader allow complete margin configuration. Koreader's default for .epub (without selecting a style) only has a small line at the top with the file name on the far left and a "page#/total pages" and a battery meter on the far right. No footer.
https://www.mobileread.com/forums/sho...d.php?t=226456
You can add them without effecting your Kobo software in any way. In fact the alternative readers launch in the same manner as selecting a book.
Luck;
Ken