The only info I was able to find was various references on video game websites. Those appear to be sourcing the information from discussions found on Twitter and/or Reddit though. So it goes without saying they should be taken with a grain of salt. I can't say I routinely visit those type of websites because... reasons. But I'll throw a few links here anyway.
CD Projekt Red has stated that players will be able to craft most items in the game with the Cyberpunk 2077 crafting system, with two exceptions.
www.vgr.com
CD Projekt RED reveals more about how Cyberpunk 2077's crafting system will work, telling fans some of the items they'll be able to create.
gamerant.com
I believe the first link is using a Reddit conversation as it's source while the second is going off a Twitter discussion. I checked a few others but, again, they all seem to be sourcing the comments from one of these two conversations.
To respond to your second question about how I'd like to see it handled... I guess as it is in every other similar type of game. Weapons, armor, vehicles, modifications where applicable, etc. Find stuff in the world and, assuming the character has the proficiency, manipulate it to gain an improvement somewhere.
The only part I'd add to that generalized view is integration with the engineering, or Techie, aspect of character progression. As in, a character progressing toward that end has a better ability to do this type of stuff. Primarily because it is a good way to add to the unique appeal of this particular path. The game may use a "fluid" class system but any quality RPG progression has pros, cons and differences related to pursuing any given path. A fluid system isn't mutually exclusive with these differences.
