Third post in a row - Stable or Rolling. Yes, it can make a difference.
The author of the web page - web site of howtos to help remind himself and others seems competent - capable. Target is Buster which would be Stable in Sparky at present. Skill set is somewhat high.
Unless you have a solid reason to use F2FS, I recommend sticking with the file systems offered by the Debian installer instead. The method mentioned here is not official. The very reason why I am updating this guide is that an update to the F2FS driver in the Linux kernel a few years ago brought additional kernel module requirements, making the systems set up according to my previous guide to F2FS unbootable. Also, F2FS may not work with some extended file system attributes, such as those used by SELinux.
The SELinux comments might have some bearing.
The Arch Wiki can be helpful at times. Never follow it blindly. Great info.
https://wiki.archlinux.org/index.php/F2FS
Debian Wiki
https://wiki.debian.org/F2FS
I do wish you luck. I have run separate DE's on SDHC's in atom's in the past, but it is something that I would have been interested in the past, but at present I take care of people at work and my parents at 96 and 90. Of course look at the Debian Forum to look for solutions. A lot more users there,