Are you holding the mod to your ear to listen for sizzle? If so, stop. The wire does have to cool..............and you may have better hearing than many assume.
After seeing your builds, My concern now is your interpretation of Burnt hits.
A burnt hit is not something one would ordinarily ignore and continue vaping past.
True burnt hits are NASTY and ruin Cotton wicks.
Did you get New wire when you received the New RDA?
Are you wiping the wire clean(alcohol) and Dry wiping with a Paper towel before building? Dirty/oily residue can impart nasty taste.
Are you doing good dry burns on new coils?
Are you OVER Dry burning? This leads to Center grommet Melt and Nasty taste.
I'm starting to believe you keep trying to fix something that is not broken and missing the actual issue.