This is what I run. Had to get a second light on my flex because the one just wasn’t enough. Actually looking to see if there has been anything further found or done with these lights. That’s how I found your post.
I get good growth on some euphyllia and some zoas. Just to give you some ideas on what I have in my tank.
I personally have the Aquasky on mine. I didn't realize at first it wasn't the fluval marine light. The aquasky is decent, but I'm going to get a second aquasky. But I have noticed the Par values, light spread, and color spectrum is MUCH better on the Fluval Marine. I wouldn't worry about not being able to care for corals. I would use the auto or pro setting, and mess around with it. Maybe like 9 hours of lighting (unless you have a new tank since a ton of lighting isn't completely necessary), but I have ramp up and down periods so it's more like 8 hours of good lighting. I wouldn't worry about keeping corals and nems. I have a Stylophora on the top of my tank and it's looking great! But you're lighting such be fine. Also I'm not sure if you're new, but phosphates are important, and make sure they stays reasonably low (mine crept VERY HIGH) and the corals were blander in color and weren't growing. But Frogspawn really like the tank, and Blastos! It amazes me how good the Blastomussa look despite not getting much light. But you shouldn't worry about the light not being strong enough.
You could add a small Aquasky which is 55 ish dollars in the future if you need a slight increase, but I think you should be good!
I like to have a cyan type color during the day, and transition to a light purple color (sorta like a sunset), and then I have blue actinic at night. But it might take time, but just mess around with it. I can't give exact settings since mine has 4 light colors, and the Marine has 6!
Heres mine with 1 light bar from 9am to 930pm. I’ve been messing around with the white most times it peeks at 50% the light is not strong so that’s why I have it higher right now to see if the softies like it.
Oh I also have a gbt nem that’s huge and 1 rbt that split recently in less than 6 months