No, Franky, First-Seen rules protects against someone using RBF to steal 0-confs away, you've been told 1000's of times and yet you still repeat-repeat-repeat-repeat this BS propaganda
Well, to be fair, there is Opt In RBF. If a transaction is non-final (sequence of any input is not 0xffffffff), it is either timelocked or uses opt in RBF which means that the transaction could be replaced.
check the transaction has a fee
That won't always be true even today, zero-fee transactions still get processed. To be fair, this is the only piece of advice that has a semblance of truth (and I think we all know Franky relies on making his BS more palatable by mixing it in with some obvious facts)
I would also like to add that the transaction has to have a high enough fee, not just a fee in general. Low fee transactions still take a while to get confirmed.
check the taint of the inputs
And here Franky reveals exactly the kind of boot-licking corporate shill he really is: one of the fundamentals of Bitcoin is to transact fungible money without censorship, and here's Franky, telling us to censor transactions (the irony shouldn't be lost on anyone who knows Franky for what he is: he goes on and on and on about non-existent censorship on this forum to disparage genuine supporters of Bitcoin)
That ,I agree, is complete BS.
Additionally, when accepting unconfirmed transactions, you should also check whether the inputs of the transaction are also unconfirmed.
I think one of the biggest factors of not having Bitcoin in accepted in physical stores is that employees need to understand how to use Bitcoin too before it can be accepted.