I think that RBF is a good option for you, especially since the transaction already supports it. There is no need to wait for nodes to forget your transaction, you can regularly check mempool.space for recommended transaction fees (they are very accurate) and when you see that fees are going low, don't risk and ask your friend to increase transaction fee via RBF. I wouldn't suggest to wait till nodes forget your transaction because you never know what's going to happen in terms of fees, you might not see anything below 100 sat/vByte for a month or two. If it worth for you to wait that much, then never mind what I suggested.