Has anyone had any success in finding a server on Electrum, Sparrow, or another popular wallet that supports broadcasting of transactions that pay below 1 sat/vByte? Besides Blue Wallet, have other software clients signaled that they will make changes in this regard?
You might want to try using Bitcoin Core with the following entry in your bitcoin.conf file:
settxfee=<your_desired_fee>
According to [urlhttps://bitcoincore.org/en/doc/22.0.0/rpc/wallet/settxfee/]official documentation[/url] this parameter has replaced the older paytxfee option starting from version 22.0.
If you're using Bitcoin Core not only as a wallet but also as the full node consider adding the following as well:
minrelaytxfee=<your_value>
P.S. I've noticed that transactions with fees below 1 sat/vB are becoming increasingly common, which definitely is the nice move.