Set bitcoin fee lower than minimum estimatesmartfee value Currently when I broadcast transactions, I seem to be unable to do so with a fee below ~10^-4 bitcoin (~$2 at current exchange rate). Any 'conftarget' value between approximately 100 - 1000 yields the same ~10^-4 estimate. I would prefer to send some less urgent transactions with lower fees but it's not clear how to do so if when I set conftarget=1008 (which I believe is the bitcoin core max) for the transaction, I cannot access fees lower than described. Is this expected behaviour for Bitcoin Core?
On a related note, it is not completely clear to me how the estimatesmartfee 'estimate_mode' parameter functions. From the help, I can see that the options are 'ECONOMICAL' and 'CONSERVATIVE', which seem quite self-explanatory on a high level (former estimates lower fees than latter for same conftarget), but in practice - how does the estimation differ? So far I have used the default 'UNSET', which I understand defaults to 'CONSERVATIVE' - would this affect the value of the apparent minimum possible network fee described above?
Regarding your first question, a new fee_rate argument has been added to the sendtoaddress command in the upcoming release (v0.21.0, currently at the third release candidate) of Bitcoin-Core.
In addition, a new send RPC was integrated which allows you to set a specific feerate too.
Regarding your second question (meaning of CONSERVATIVE and ECONOMICAL), see How does Bitcoin Core estimate the transaction fee? .