ICT is expected to form 21% of global electricity demand in 2030, and history has shown that efficiency gains in Internet infrastructure aiming to curtail such impacts are far outstripped by the growth in data traffic. We need to reduce demand for Internet connectivity, yet encouraging moderate interactions with digital devices and online services could potentially benefit users. HCI designs have been suggested for moderate interactions and Internet usage, most commonly on smartphones - but it's currently unclear whether these interventions can actually be implemented and tested to understand the user and environmental impacts. In this paper, we review features for understanding and manipulating data traffic in accordance with the stock Android and iOS development libraries to better scope the potential for implementing moderate and sustainable digital experiences. Specifically, we outline the intervention features plausible for Android implementation, and we provide reasoning for why iOS is currently too restrictive.