rqlite[1] creator here, happy to answer any questions. rqlite also supports read-only nodes, which can also help with reads at the "edge". It probably wouldn't scale to 100s of nodes, but it is an option.
"rqlite supports adding read-only nodes. You can use this feature to add read scalability to the cluster if you need a high volume of reads, or want to distribute copies of the data nearer to clients – but don’t want those nodes counted towards the quorum. These types of nodes are also known as non-voting nodes."