CEO Lei Jun recently revealed that MIUI 11 will cut down on ads and remove the vulgar ads too. Now, Xiaomi’s MIUI Experience Chief has revealed in a Weibo post that the company has already begun testing a feature that will let users opt out of seeing ads in MIUI. The feature has been implemented in the form of a switch that can be used to enable or disable ads.
The post further adds that Xiaomi began testing a new ad system in MIUI after receiving a lot of negative feedback from users. “[Xiaomi] can confirm that [the ad switch] is being tested. MIUI in China will be rolling out an update with an option to switch off display ads with MIUI  9.8.29. This will affect system apps (such as Calendar, installer, Download manager, etc.).
MIUI’s ad switch feature is currently being tested in China, but there is no word if, or when, will it make to other markets. As for the switch, it will reportedly be accessible from this path in MIUI: Settings > Privacy Agreement, etc > System tool Advertising. Moreover, it is currently available only in the development version of MIUI 10.9.8.29 or a later build.