Light; ¿Ive got more than enough?

Hello,
I got a flowering room (only flowering) with the following measures
Height: 110 Cm Width: 60 Cm Lenght 45 Cm...

In this space im able to put 4 "manifolded" (main lining) plants in 7 liters air pots...
I started the room with an 250 watts HPS inside a cool tube, but i felt that something was missing from my buds so i added 2x Vero29 Cob Lights 50 watts each, and the yield and quality of the harvest improved a lot, now i made another upgrade, cause i had a magnetic ballast and for safety and heat managment i decided to buy a dimmable electronic ballast of 400 watts so now i have 3 options on the hps 200-300-400 watts (besides the cobs). So for the summer the 200 will be great as get kind of hot in my country, but almost always even in the not so hot period of summer (like 1.5 months) its just fine with 300 watts and im gaining 50 watts vs my previous setup, now for the fall-winter season im not sure if it would be convenient to use the 400 watts setting or just leave it in the 300 watts.

Im asking this cause a lot of people have said to me when i wanted to add the cobs that it would make no difference as i already had the "limit" of healthy light for my space, but obviously they were wrong, however i believe the "logic" behind the theory could be right and may apply this time? (with time i will experiment all the possibilities but i'm curious about your input guys!) Thanks!

You want anywhere from 35 to 70 watts per sq. ft of surface area.

More is a waste I think and less is not going to give you really good results.

50 to 65 watts per sq. ft of surface area is a good zone to be in.

In a test room I added light until the limit of hourly absorption was reached (1600 umol on the leaf). This took roughly 300 watts per square foot. I say roughly because the leaf surfaces receiving light were less than the growing area and some of the lights were a focused beam.
The sativa clones used at that time grew most rapidly at an average 110 watts/square foot (1050 umol). This is hybrid CMH/LED overhead lights.
Later when switching to indica, the numbers were less, 90 watts/square foot (850 umol) was more than enough.
Good growth continued all the way down to 75 watts/foot, then the drop in yield grew exponentially.
Spectrum can move these numbers by over 20%, wavelengths count.
Plants continued to grow and bud at 300 watts/foot, but were severely stunted with distorted leaves. Under 50 watts/foot the buds were subpar in density and potency.

To avoid confusion, humidity, temperature, nutrients, and air quality all have major effects on growth as well, possibly overwhelming any system of lighting. Plants can grow poorly or die outside under genuine 100% sunlight.