How many confirmations on the input? Many pools still take coin age into account when including transactions in a block, it's not just a straight highest fee formula yet. (Despite any propaganda to the contrary to justify it's future removal).
i seriously doubt that. the priority formula is long dead.
No it isn't yet. I've made low fee transactions which have been prioritised over higher fee transactions recently.
If you look at the block delay estimation on
https://bitcoinfees.21.co/ there is a lower bound and an upper bound. Currently some transactions in the 1-20 sats/byte range are being confirmed after 5 blocks, where other transactions in that range might not be confirmed at all (5-Inf). 101-120 sats/byte range show 1-18 blocks delays. So some lower fee transactions are being confirmed in 6 blocks, whilst some of the higher fee transactions are taking 19 blocks.
BW, BitFury, ViaBTC, GBMiners are examples of miners that have included my high coin age lower fee transactions ahead of higher fee paying transactions.
Antpool and F2pool seem to be the pools that will mine non-full blocks despite fee paying transactions being in the mempool and having plenty of validation time between blocks.