It might look nicer with spaces. Also deleted some unnecessary test files.

build/etc/default/grub

@@ -1,6 +0,0 @@
-
-# Name and mail address of owner
-#OWNER="John Doe <john@doe.tld>"
-
-# Amounts of seconds for how long the owner information is displayed. It is skippable via ESC. Default: 5
-#OWNER_TIMEOUT=5

build/etc/grub.d/000_ownership

@@ -1,51 +0,0 @@
-#!/bin/sh
-# Author: Bandie <bandie@chaospott.de>
-# Copyright: Bandie, 2019, GNU-GPLv3
-
-set -e
-
-## Get params from /etc/default/grub
-OWNER=$(cat /etc/default/grub | egrep "^OWNER=.*$" | sed "s/.*=\(.*\)/\1/;s/\"//g;s/'//g")
-OWNER_TIMEOUT=$(cat /etc/default/grub | egrep "^OWNER_TIMEOUT=.*$" | sed "s/.*=\(.*\)/\1/;s/\"//g;s/'//g")
-
-
-## Check if OWNER is set
-if [ -z "$OWNER" ]; then
-	echo "/etc/default/grub: No OWNER set." >&2
-	exit 0
-fi
-
-## Notify user about ownership
-echo "Show ==> $OWNER <== as owner" >&2
-
-
-## Generate spaces in case if the owner has a very short name
-for ((i=${#OWNER}; i<6; i++)); do
-	NSP="$NSP "
-done
-
-## Generate border around the owner message
-B="##########"
-for ((i=6; i<${#OWNER}; i++)); do
-	B="${B}#"
-	SPACE="$SPACE "
-done
-
-
-## Check if OWNER_TIMEOUT is set. If not, default 5
-if ! [[ $OWNER_TIMEOUT =~ ^[0-9]+$ ]]; then
-	OWNER_TIMEOUT=5
-	echo "/etc/default/grub: No OWNER_TIMEOUT set. Using default: 5 seconds." >&2
-fi
-
-## Write it into the grub.cfg
-cat << EOF
-echo ""
-echo "$B"
-echo "# Owner: ${SPACE}#"
-echo "# $OWNER $NSP#"
-echo "$B"
-echo ""
-echo ""
-sleep -i $OWNER_TIMEOUT
-EOF