How much do differences in typical flux add up once a light starts driving an LED at higher currents?

I'm working on modding my Sofirn Q8 by simply reflowing with 3V Luxeon MZs. I'll be using diffusion film to fix the MZ's "donut hole" effect. I plan to go with a warm tint, 3000K or 3500K, and I'd like to go with as high a CRI as possible. The goal is to preserve, and preferably increase its hot rod status, while also benefiting from a warm tint and relatively high CRI.

The typical flux for these emitters varies in different CCTs and CRIs, as always. For instance, the 3000K 80 CRI has a typical output of 781 lumens at 2800 mA, while the 3000K 90 CRI clocks in at a typical 640 lumens at the same current.

I'm wondering if anyone can give me a sense of how big of a difference in output this will make at the high currents the Sofirn Q8 is capable of pushing. If it were just a difference between 781 and 640 lumens, I'd probably go with the higher CRI version; however, I suspect that the output difference is not linear and the gap will widen as current increases. If anyone can give me an idea if I'm correct about that, and how much of a difference it might make for this hot rod, I'd appreciate it!

This will give you a first idea : LED test / review – Lumileds Luxeon MZ 5700 K min. 90 CRI (3V)

Thanks, that was both informative and interesting.