I was doing something very similar to telelumen but given the variation in LED spectrum you could get off aliexpress in 2020 I could never hope to match their quality without tuning each led separately.
Looking at the spectrum graphs for your lights I'm seeing the telltale phosphor coating spike for both warm and cool white leds. An understandable tradeoff, but with the brightness of monochromatic LEDs you can get today one that's not essential any more.
With the drop in costs for both controllers and pcbs since then you should be able to get telelumen quality temperature spectra without the matching price, especially if you can get LEDs that have consistent spectra for their nominal wavelength - you only need to tune the controller once instead of for each light.
Yes, the more LEDs you mix the closer you can get to your target SPD but more LEDs also add cost and may not fit mechanically depending on how you are mixing them.
One other variable is energy efficiency, there are a lot energy codes around the world that limit how much energy you are allowed to use to light a space. In California for example it can be 0.6w per sqft. Sunlight is more like 100w/sqft so you end up having to optimize the spectrum for what humans can see and feel. I like to compare it with jpeg compression for light. In jpeg we throw away components you can’t see very well, you can do the same for light for an energy efficiency sake and maintain a close perceptual proxy.
We found 4 chips is a minimum bar for good light and use 5 for virtual sun - more info: https://www.innerscene.com/products/circadian-sky/CircadianS...