As far as I can tell, they are no different than normal SCs, except that they can be bid early. So to answer your question, yes.

Comms on this from all fronts is extremely lackluster.

I have seen no indication whatsoever that you would have any protection to actually sit one of these SCs. By that I mean, if you were awarded a SC via this new bidding method, there is a possibility that you could still be assigned something during next-day/second-day trip coverage that could overwrite the SC.

One could presume that you are in pre-assigned rest for 18 hours preceeding the first of these awarded SCs, and this might eliminate LC from your schedule if the awarded SC is on the first day of a stretch of LC days, therefore unavailble for next-day/second-day assignment (and the 10-18 hour carve for coming from an off-day.)

But what if you were awarded SC on day 2 of a stretch of LC? Nothing to prevent a 5-day trip assignment on day 1 of the LC stretch that wipes out your awarded SC?

So many questions.