Glad you’ve got things (more) under control.
That 5V supply is a little on the light side for my tastes, but don’t argue with success at this point…
As far as the 12V supply requirements, the best way to know what your LEDs draw is to measure the actual current for 20 LEDs at 100% White. That will give you a real number you can use to predict the worst case draw for the whole strip and what your power supply needs to deliver.
Incidentally, the brightness limiter values are only calculations based on what you tell WLED about your setup. It doesn’t actually protect your power supply at all, that’s what your real world power calculations are for.