is there a way test which node support full-rbf?

[hotbroker]

i do some reseach ,gpt tells me try to utilize the GETDATA p2p command, like brocast to all the nodes i connected,and check which send me back r txdata

[petertodd]

If you're trying to do actual research, the best bet is to create a full-rbf replacement pair and actually broadcast it to the node you're testing and see if the second tx propagates. Everything else is uncertain, as the super majority of nodes with full-RBF enabled don't advertise it.