@laanwj, my understanding is that most SPV clients at the moment either get headers from a centralised source (Electrum) or use their own p2p network. I don’t know, some may use the main Bitcoin network, but wouldn’t they be queried for blocks by other clients and have to ignore those requests which could confuse the other peer (maybe?). I think it would be neater if other peers knew that you could be asked for headers, but not for blocks/txs. Anyway, sorry to bring up an old issue. Just thought someone should start working through the massive backlog, so I started from the back.
Re: Block-header-only, faster startup client
Figures: bardiharborow