Is it worth adding an extra LED light for flowering?

You won't get 60 bucks more in bud but a bigger bill for two months.

I would honestly just lower the light you currently have in your grow. I’d try hanging 8-12” above the canopy. 25 watts per square foot is sufficient for flowering alone. You could add more light up until 50w/sqft. I would look for a light tailored to flowering though, with more red light than others.

Your current light is rated for a 60*60cm flowering you should have plenty of light for flowering. But if your do want more light get one for flowering. Reds 2700k- 3000k. Don't want any blue with "supplemental" flowering lights.

Looking at your diary I think is a good idea to add some light more. Have a good grow. 💪