At https://github.com/bitcoin/bitcoin/issues/22404#issuecomment-874168305 no explanation is given for a peculiar rule about estimating fees, that "you have to wait around for a couple of blocks after being synced before fee estimation will work."  The rule is true, but it needn't be true, and the software would be more useful if it were not true.  If it does seem impossible to break this rule, perhaps some brainstorming is in order.  I estimate fees quite often on my own, although I am trusting the block explorers in their reporting of the fees for the most recent blocks.  The software doesn't need to trust anything once it has been synced.