It's good to know I wasn't the only one with drone issue here!!
I've tried different combinations, and none of them was significantlt diffeent enough. Although I wasn't up for spending much money to resolve this, the cork thing kinda confirmed the vibration is either the source and/or a contributing factor, so I am about to try this reinforced bushing since it's just 20 clamps from amazon. The exhaust sounds so good without the VRRROOOMM drone around 2k rpm.