I believe blastr is write-only (you write there, it will spread through other relays), but nostr-proxy seems able to do read and write:
I think the guys over at Mutiny Wallet have a possible solution: the blastr relay.
https://github.com/MutinyWallet/blastr/blob/master/README.md
I believe blastr is write-only (you write there, it will spread through other relays), but nostr-proxy seems able to do read and write: