This makes perfect sense. 100% guaranteed message delivery does feel impractical from an engineering standpoint, and would definitely end up bogging down the network - either through one-shots or awaited calls. However, it’s common for applications to handle brief spikes in traffic where a queue or the network will temporarily get behind - while it’s convenient for the network to throw away requests, developers who are focused on a top-tier end user experience need to build in excess capacity to handle “reasonably expected” spikes in traffic and to hold onto backlog for a certain amount of time.
Awaiting calls then imposes its own throughput constraints via canister output queue limitations.
Is this live? Are there any implementation examples in Rust or Motoko?
What about the case where awaiting on a call from a 3rd party canister that is stalled?