It depends what fountain codes are intended for. On the client side for splitting large files into smaller parts fountain codes would be fine. On the network side fountain codes for reducing storage and bandwidth requirements (compared to pure redundancy), many people have discussed at length in Are Erasure Codes better than Replication for the SAFE network. I address redundancy vs erasure codes in the linked post #94 in the section for p19 (see quote below). Not a topic for beginners, but you seem to be good with analysis so hopefully can add some more insight in that topic.
The secure messaging algorithm for traversing xor space makes it much less practical to track and repair files via erasure coding.
For this reason I think erasure codes are fundamentally unsuited to being used at the network layer of the SAFE network. However they may still be useful at the client / app layer.
The RFCs are good to read and I personally consider them the very top of the tree of truth wrt documentation. I have pretty-much stopped using any other documents for technical information (mind you I’m currently heavily focused on backend and almost nothing api/client-side so ymmv).
Looking forward to hearing your thoughts, and enjoy the reading (I know I did when I first came to this community).