And Motorfest was originally developed as a DLC for TC2, so it has to be compatible with TC2 in terms of the underlying mechanics.
While it started out with the intent of being DLC for TC2, it says here that it became a separate game because they wanted to do things that were not compatible with the TC2 engine:
Stéphane Beley and Julien Hummer have confirmed how The Crew Motorfest came to life over a four-year period ahead of its release.
traxion.gg
“We started with the conception to make sure that the progression and the way it was working with the activation of playlists with IRL footage, working events and the overall progression. [This was] not compatible with the main game [The Crew 2].”
So at some point the underlying tech became separate, I don't think it's possible to say what code is shared or not shared. Just because an element looks almost identical doesn't mean it wasn't re-implemented from scratch. I know someone who was contracted to port a console game to PC a long time ago and he was just given a console with the game, and told to write the same thing for PC, he had no access to the console code, so that sort of thing does happen.
On a separate subject, I've been trying to get platinum in the summit on a brand new account that hasn't played TC2, using loan vehicles for the 3 events that need specific vehicles, i.e. my aim was to not buy the bundle as it's 1.8m credits, and my feeling is that a new player really isn't going to want to spend that in-game money on 3 cars that are unlikely to be used much after this week. I can crew up with myself to do the events with loan vehicles as I have 2 PCs. I think I've probably managed to get platinum now, I'm on 1267k, which is in the top 8000. The game launchers say I've played for 14-15 hours to do that, so I feel like even that is probably more than the vast majority of new players would be willing to do in their first week of getting the game. What did I do in that time?
1. I picked the Honda starter car and did the 911 Legacy playlist.
2. I used the Porsche Timeless edition reward car to grind the GP event till I had all parts at 750.
3. Having done that, I had enough money to buy the bundle for the Ocean n Sky playlist, which got me a plane and boat. I played through that playlist.
4. I bought the bundle for Electric Odyssey, choosing that playlist because it has a hypercar reward car, and also gives access to the Hummer E-xpress event. I played through that playlist.
5. I used the Evija Pure Edition reward car to grind Hummer E-xpress to get my hypercar to max number parts.
6. I used the Frauscher Demon to grind Yacht Surfin' to get my powerboat to max number parts.
7. I used merge and recalibrate to get myself pink parts with 6+% skilled for hypercar and powerboat.
8. I used hypercar for the slalom, and hypercar+powerboat for the bullseye, and the pink parts with skilled let me get decent scores for those.
9. The Porsche Timeless Edition is reasonable for the Power event when the parts are at 750.
10. I couldn't get a very good time with the Evija for the hypercar event, so I bought the T50, which I was willing to do as I feel it would be a great long term purchase for a new player, and it's a cheap hypercar. I went 6 seconds quicker than I did with the Evija.
11. For the speed trap, I used a hypercar, as it's painful grinding dragster parts. I did a fair bit of flying around with the plane for treasure crates to open with the dragster. If I hadn't bothered with that, my summit score would be the same, so I think it would probably be possible for a new player to get platinum in more like 10 hours, as I did some other things that didn't end up being used, too.
I'm above 1400k on my main account, the biggest score killers are the speed trap and the Ford GT event. My score is 50k lower with the Ford GT loan car and no legend points. I think the speed trap might be also around 50k lower.
One thing I discovered is that you can merge 3 blues to 1 pink even if only one of the blues is max number. So if you keep all the parts as you're levelling up a vehicle, you almost certainly can make a max number pink as soon as you have just one max number blue. This made it extremely easy to get a full set of pinks for each vehicle type.
I did all that because I was going to get a friend to play the game a bit with me, but there's no way he'd want to do more than maybe an hour a week, and also he's much less skilled than me at driving, so I can see now that there's no way he's getting platinum in a summit, and I'd have to plan more long term, like do 1 playlist a week for 3 weeks to get access to main stage, then maybe level up one vehicle category a week to get the main categories levelled up etc.