I have 2 PBX, 1st in google cloud v15 and second on-prem v16.
Why those 2 systems have totally different SIP Trunk Inbound parameters? (v15 have much more options)
For the most part, when changes such as this (simplification of options) is made, it's because on the older version, they were found not to be necessary.
Incorrect use, by persons not completely familiar with their individual functions, may have caused unnecessary trouble tickets to be generated.
Someone at 3CX would have to provide the definitive answer.
As @leejor pointed out, most of these headers were useless, from an inbound call the only things we are interested in extracting are the Caller ID, Caller Name and Destination Number, those are the only things we can use.
So, we decided to remove the rest of the options to both "clean up" the page and give a smaller possibility for error if someone wants to configure something manually.