I would say VT's "milepoint exit XX" panels don't count. They're barely posted and one cannot navigate by them. I feel like the "next exit X miles" panels on the Thruway are more prominent (probably because those are at least
consistent with which sign in the sequence they're on).
For DE:
-I-95 and I-495 are sequential
-DE 141 is close enough
-US 301 is mile-based
-DE 1 is a huge mess of km-based numbers on the older exits (despite all distance signs and mile markers being in miles) and mile-based subtracted from the last km-based number on the newer exits. In short, it's a hybrid mess where the numbers match nothing.

For DC:
-I-295 is close enough
-I-395 is sequential (we'll see what happens when the changes from I-395/I-695 to I-395/I-195 happen)
-I-695 and DC 295 (what few numbers exist) are mile-based.
For NY, I-890/NY 890, the NYSDOT part of I-95, I-781, I-99, I-84, the Taconic, and the Hutch are mile-based, and I-81, BL 81, NY 481, and I-690 (not sure if NY 690 is getting numbers) are planned to convert within the decade. I am aware of no other plans for conversion at this time.
NH, meanwhile, wants to convert, but needs to replace their governor before said conversion can happen.