Philips Hue will keep its limitations. The LIDL Christmas lights are Tuya based and as such use different types of Zigbee commands.
For Phoscon (deCONZ) bridge, this is “translated” which we use in Hue Essentials. Developers at deCONZ worked hard on this. We then integrated all in Hue Essentials.
When it comes to Philips Hue, there is no API which makes this adaption. Any command we send will get there but receives a possibily wrong interpretation.
I doubt Signify will update their bridge for such third party devices with alternate Zigbee commands. Just like they did not integrate devices like the Trådfri smart controls.
You are right about the brightness point to correct colours.