"Destroying the mask doesn’t contradict TLJ. Destroying the mask was out of frustration of being a knock off and failure to live up to Vader, not necessarily to let the past die. When Kylo said let the past die, he meant the Jedi, the Sith, the Empire of Old, etc. and make the future his way, a new order as per his vision.
He resurrected the mask because he felt confident that he could live up to Vader in turning Rey dark and killing Palpatine. He openly told Palpatine twice that he’d kill him after being subservient to Snoke, and actually succeeded in turning Rey to the dark side before Leia turned him back."
Yup. This is pretty much what I’ve been saying for a while now. He was trying to finish what Vader started by letting the past die; get rid of everything except for a new order ruled entirely by himself and those he cares for.