There’s some info here:
My guess is the photometric data will look like this, from a different Philips bulb:

One user measured a similar spectrum from these specific bulbs here:
I haven’t noticed anything unusual in the dimming behavior. The CCT lowers. Maybe at the lowest level it gets cool again, but it’s hard to say. Our eyes aren’t that good at recognizing color in extreme darkness.
I’ll measure the flicker percentage, but it looks very good. I’m not sure how they did it. I can see a 12 uf capacitor in the bulb. I’m guessing there is an IC in there, since it has a delayed turn on. Maybe a linear regulator to even out the remaining ripple? But no idea how they did all that with no external cooling. I might have to tear down one to see the inner circuits.