Excellent writeup. I’m a retailer that has accepted about 500k USD worth of 0-confirmation transactions and had no incidents of fraud due to just waiting a minute or two before processing. Sometimes it can be an hour between blocks and I didn’t want my customers to have to wait more than a minute or two for their gift cards.

I’ll write in the RBF detection code but I’m very frustrated at the direction this is going.

I’m also in the midst of writing a Bitcoin payment processor and this puts a hamper on a lot of the features I was planning on implementing