All of the above is correct, except last sentence.

See attached pics. You will get a 60 day Colorado temporary registration, shows no fees for that. Then see the CA DMV registration pic, add up all the fees, it will come to $600, unless the State raised them since then. Plus, the use tax (sales tax), which i25 collects and remits with a check to the CA DMV with the packet they send to the DMV for final registration.
Note: the blue ink correction was done by DMV, as I screwed up my original 343 DMV form. i25 also submits a 343 in their packet as mentioned above.

You have 20 days to register in CA, (after the vehicle enters CA) per CVC. CA DMV will issue a 30 day temporary, if the documents are not in their possession by the 20 day requirement and you would have to go back. If you don't attempt to register by the 20th day (which you declare on form 343), fines will occur, this happened to another CA Telly owner....by one day.
KEYS:
●Select the DMV you want the i25 documents to be sent to, tell your sales person the address, reiterate upon pick up at i25. They get a lot of CA buyers and their document person sits on the paperwork (at least for me). I had to follow up with email to i25 after they didn't send docs at my first DMV visit. That prompted next day air delivery to the DMV I had selected, as I requested a tracking number from i25 in my email and texts to my sales rep. Just a heads up on that.
Also, let your sales rep, no i25 emblems, website stickers on your Telly.