diff --git a/commands/dorothy b/commands/dorothy
index 83b427017..29d35b831 100755
--- a/commands/dorothy
+++ b/commands/dorothy
@@ -114,6 +114,7 @@ function dorothy_() (
 			dorothy install
 			  [--clean]
 			  [--skip-install]
+			  [--user=<user>]
 
 			    Installs Dorothy interactively, with configuration for dotfile modifications.
 
@@ -901,6 +902,8 @@ function dorothy_() (
 	}
 
 	function ensure_user_configured {
+		local user="${1-}"
+
 		# sanity check
 		if ! [[ $action =~ ^(install|update)$ ]]; then
 			return 29 # ESPIPE 29 Illegal seek
@@ -915,27 +918,46 @@ function dorothy_() (
 			fi
 
 			# prepare
-			local question='' user='' where='' cli='' repo_git='' repo_url='' repo_name repo_description local_ip
+			local question='' where='' cli='' repo_git='' repo_url='' repo_name repo_description local_ip
 			repo_name='dotfiles'
 			repo_description="My user configuration for the Dorothy dotfile ecosystem: $dorothy_homepage"
 
-			# check where they want to store the user config
-			if is-interactive; then
-				where="$(
-					choose-option --required --label \
-						--question="Where do you want to store your Dorothy user configuration?" \
-						-- \
-						github \
-						'Use a GitHub repository for your user configuration.' \
-						gitlab \
-						'Use a GitLab repository for your user configuration.' \
-						custom \
-						'Manually specify a repository URL for your user configration.' \
-						'local' \
-						"Don't use a repository for your user configuration, just store it locally for now."
-				)"
-			else
-				where='local'
+			# handle github and gitlab prefixes, local value, custom urls, and default github usernames
+			if test -n "$user"; then
+				if [[ $user =~ ^(gh|github): ]]; then
+					where='github'
+					user="${user#*:}"
+				elif [[ $user =~ ^(gitlab|gl): ]]; then
+					where='github'
+					user="${user#*:}"
+				elif [[ $user =~ ^(local|none)$ ]]; then
+					where='local'
+					user=''
+				elif [[ $user == *:* ]]; then
+					where='custom'
+				else
+					user='github'
+					where=''
+				fi
+			fi
+			if test -z "$where"; then
+				if is-interactive; then
+					where="$(
+						choose-option --required --label \
+							--question="Where do you want to store your Dorothy user configuration?" \
+							-- \
+							github \
+							'Use a GitHub repository for your user configuration.' \
+							gitlab \
+							'Use a GitLab repository for your user configuration.' \
+							custom \
+							'Manually specify a repository URL for your user configration.' \
+							'local' \
+							"Don't use a repository for your user configuration, just store it locally for now."
+					)"
+				else
+					where='local'
+				fi
 			fi
 			if test "$where" = 'github' && __command_exists gh; then
 				cli='gh'
@@ -944,15 +966,17 @@ function dorothy_() (
 			fi
 			if test "$where" = 'github' -o "$where" = 'gitlab'; then
 				# prepare username default, and clear generic usernames
-				user="$(get-profile username || :)"
-				if test -n "$user" && is-generic -- "$user"; then
-					user=''
+				if test -z "$user"; then
+					user="$(get-profile username || :)"
+					if test -n "$user" && is-generic -- "$user"; then
+						user=''
+					fi
+					user="$(
+						ask --required --confirm \
+							--question="Enter your $where username." \
+							--default="$user"
+					)"
 				fi
-				user="$(
-					ask --required --confirm \
-						--question="Enter your $where username." \
-						--default="$user"
-				)"
 
 				# check what they want to call the repository
 				repo_name="$(
@@ -1360,7 +1384,7 @@ function dorothy_() (
 
 	function act_install {
 		# process arguments
-		local item option_clean='no' option_skip_install='no'
+		local item option_clean='no' option_skip_install='no' option_user=''
 		while test "$#" -ne 0; do
 			item="$1"
 			shift
@@ -1368,6 +1392,7 @@ function dorothy_() (
 			'--clean' | '--clean=yes') option_clean='yes' ;;
 			'--no-clean' | '--clean=no') option_clean='no' ;;
 			'--skip-install') option_skip_install='yes' ;;
+			'--user='*) option_user="${item#*=}" ;;
 			'--'*) help "An unrecognised flag was provided: $item" ;;
 			*) help "An unrecognised argument was provided: $item" ;;
 			esac
@@ -1384,7 +1409,7 @@ function dorothy_() (
 		if test "$option_skip_install" = 'no'; then
 			ensure_minimal_dependencies
 			ensure_machine_configured
-			ensure_user_configured
+			ensure_user_configured "$option_user"
 		fi
 		ensure_shell_configured --clean="$option_clean"
 
diff --git a/commands/ssh-helper b/commands/ssh-helper
index 45b26a094..5449ffd89 100755
--- a/commands/ssh-helper
+++ b/commands/ssh-helper
@@ -187,7 +187,7 @@ function ssh_helper() (
 			--find='AddKeysToAgent .+' --replace='AddKeysToAgent yes'
 
 		# trim the identity segment
-		sd -f mis '# <dorothy:SSH_IDENTITY_AGENT>.+?# </dorothy:SSH_IDENTITY_AGENT>[[:space:]]*' '' "$HOME/.ssh/config"
+		sd --flags mis '# <dorothy:SSH_IDENTITY_AGENT>.+?# </dorothy:SSH_IDENTITY_AGENT>[[:space:]]*' '' "$HOME/.ssh/config"
 
 		# and add it back in if desired
 		if test -n "$SSH_IDENTITY_AGENT"; then