in the industrial Beagle Bone Black Industrial I discover that the size percentage of /dev/mmcblk1p1 is increasing after running two exes in the /home/debian folder for a longer period of time. This happens whether I run the exes on /home/debian to raise the log size or if I install them in the /usr folder. I also use sudo systemctl services to execute the exes as services.
I assume you mean the amount of used space is increasing. Probably down to log files assuming your executable is not writing anything. If running a program as a systemd service, any prints it does to stdout/stderr go to the system log files, thus increasing the disk space used.