Open a Tab in Firefox on macOS with AppleScript

firefox-open-tab.applescript

# To run:
# osascript firefox-open-tab.applescript http://technosophos.com
#
# References:
# https://support.mozilla.org/en-US/questions/1130718
# https://stackoverflow.com/questions/3645763/how-do-i-instruct-applescript-to-open-a-new-firefox-window-with-a-link
on firefoxRunning()
	tell application "System Events" to (name of processes) contains "firefox"
end firefoxRunning

on run argv
	if (firefoxRunning() = false) then
		do shell script "open -a Firefox " & (item 1 of argv)
	else
		tell application "Firefox"
			activate
			open location item 1 of argv
		end tell
	end if
end run

I tried to minify it, but still very slow:

on run
	tell application "Firefox"
		activate
		tell application "System Events" to keystroke "t" using command down
	end tell
end run