That's rather disappointing news...
I read it this way: Tuya lacks quality control over the applications the different vendors deploy on the Tuya platform. A poorly designed (or poorly implemented) engineering solution can be multiplied many times with each different white-label company that sells IoT products based on the TuyaOS, and there is no easy way to correct this.
Anyone who has commented in this TuyaOs forum has spent a lot of time and experienced a lot of frustration trying to prevent these TuyaOS-based presence sensors from working without overloading the existing Zigbee network, where many dozens or even hundreds of Zigbee devices operate normally—until the moment when TuyaOS spamming devices are added.
It is understandable that such problems may happen sometimes. We are here to try to find a solution together :
what can be done to ask the vendors to make corrections and provide OTA updates for the mmWave presence sensors already produced and sold to the end customers? Are all these past closed projects, and Tuya has no instruments to ask for a change? (there is a cost involved in such firmware updates, of course..)
what can be done by Tuya to prevent the same problem from happening again in the future?