Hi TP Link,
I'd also like to know this too. I've upgraded to Deco X60 from the M5 as I find the kit very reliable, but this is a bit wish list item that could perfect and differentiate Deco's QoS. I have occasional issues with work from home video calls and gaming latency when others are downloading.
Given you seem switched on to making a great product, implementing this would be fantastic in market. Only the eero and some smaller niche brands have this, or in my case, needing to rely on an EdgeRouter X. I've found the built in Deco QoS not quite up to scratch for buffer bloat compared to how seamless SQM can be.
Could it come to Deco?