Just a thought, but have you tried relative tuning, rather than digitally tuning each open string? Get the 3rd string in tune to G, then tune the 4th string at its fifth fret to that open G string, then tune the open 1st string to the 7th fret of that G string, then tune the high G string to the first string fretted at the 5th fret, and then finally tune the second string at its 8th fret to the open high G string. Might not work for you, but it’s supposed to overcome troublesome intonation, especially for the B string, for which some banjos like Stellings have a compensated nut anyway. Note this relates to gDGBD tuning.