Right now, if you want to test op-rbuilder with builder-playground (guide) you have to run it with these flags:
$ $HOME/.playground/op-reth-v1.3.12 node --http --http.port 2222 \
--authrpc.addr 0.0.0.0 --authrpc.port 4444 --authrpc.jwtsecret $HOME/.playground/devnet/jwtsecret \
--chain $HOME/.playground/devnet/l2-genesis.json --datadir /tmp/builder --disable-discovery --port 30333 \
--trusted-peers enode://3479db4d9217fb5d7a8ed4d61ac36e120b05d36c2eefb795dc42ff2e971f251a2315f5649ea1833271e020b9adc98d5db9973c7ed92d6b2f1f2223088c3d852f@127.0.0.1:30304
It would be helpful to add a flag in op-rbuilder like so:
$ op-rbuilder --playground $HOME/.playground/devnet/
that would automatically set all those flags.