Mark “Murch” Erhardt and Mike Schmidt are joined by Dave Harding, Peter Todd, Abubakar Sadiq Ismail, David Gumberg, and Jeffrey Czyz to discuss Newsletter #295. News Disclosure of free relay attack (1:22) Transaction fee sponsorship improvements (9:55) Mempool-based feerate estimation (34:49) Selected Q&A from Bitcoin Stack Exchange What are the risks of running a pre-SegWit node (0.12.1)? (50:30) When is OP_RETURN cheaper than OP_FALSE OP_IF? (55:51) Why does BIP-340 use secp256k1? (56:33) What criteria does Bitcoin Core use to create block templates? (58:08) How does the initialblockdownload field in the getblockchaininfo RPC work? (1:04:45) Releases and release candidates Bitcoin Core 26.1rc2 (1:07:34) Bitcoin Core 27.0rc1 (1:07:55) Notable code and documentation changes Bitcoin Core #28950 (1:17:13) LND #8418 (1:19:07) LDK #2756 (1:23:44) LDK #2935 (1:25:55) LDK #2419 (1:27:39) Rust Bitcoin #2549 (1:32:54) BTCPay Server #5852 (1:33:36)