Gregsynth and my response combined together would be very good

Proper vocal cord closure can also lead to a clean voice without rasp which is probably the case in 95/96, smoking was probably more with range to do.

Jon's upper parts of mixed voice is sometimes heard in Power Station ERA and first 2 albums.

Mixed voice with normal larynx position or only slightly higher than normal and vocal sirens to hide the chest/falsetto flip eventually can very possibly lead to a mix that sounds the same or almost the same as your upper chest voice.

THAT WAY you can easily unhealthily drag up chest voice too high until it turns into mixed voice inevitably, due to singing muscle memory.
That is how Jon does it, even I do it. It makes most people untrained in singing think you have a big chest range.

How Jon sounded like hitting a B4 in 1996 is noticeably different from early to mid 1995, definitely due to vocal abuse and his smoking.
I think Jon's upper range might have decreased 1 half step total between 95 and 96. Maybe even his whole voice.