A couple of points:
1) Small footprint devices aren't relevant to the issue of bloating. The sensors aren't bottlenecked by bloat, the nodes are, and nodes are separate from transactors.
2) The answer in the question that you linked is accurate in that sharding is on the IOTA roadmap. There aren't any formal references to this yet, so here is a description of the aim and goal to solve this problem is:
Another approach planned to enable the IOTA client running in these very resource restrained environments is to shard the core logic and database amongst different devices that then collectively run it. Similarly to swarm intelligence, this enables a cluster of devices to efficiently make transactions without being a full node, but having reduced trust requirements from SPV and light clients.