I think I am trying to solve the same thing:
I have similar requirements, tunable color temperature, very high CRI, but I also have not found an off the shelf solution yet…
I considered simply replacing the LEDs on a hue ambience bulb, but found that taking them apart in a way that is not completely destructive is not practical. Additionally they use a very weird LED topology with some green leds (presumably to compensate the crappy white LEDs).
My current plan is to get some LED housings like these:
Then make a custom board with these YujiLEDs:
https://store.yujiintl.com/collections/high-cri-led-emitters/products/yujileds-high-cri-95-2-in-1-tunable-white-bi-color-led-smd-3032-g03-pack-100pcs
And than drive them with an external constant current eldoled powerDRIVE (from somewhere remote):
https://www.eldoled.com/led-drivers/powerdrive/50-watt/ac-pw50u-m4z0x/
I have to figure the wiring out, but I was thinking to just use the e27 for mechanical interface, and then have a separate small 4-pin connector for the DC.