Sorry for the acronym-heavy subject line, but I'm guessing if you know the answer to this question you're familiar with all of these.

To summarize:
- I have two passengers on one PNR and would like to avoid splitting it
- I am GM, the other passenger is not
- we will both do OnLine Check-In
- I would like to SDC to a later flight, the other passenger will not
- The other passenger needs to check bags, I do not

My questions:

- If we both have boarding passes and arrange for the other passenger's checked luggage through OLCI, but I don't show up and later SDC when I hit the 3 hour window, is that OK?

- By the same token, if my fellow passenger has benefitted from SkyPriority, increased baggage allowance, and free EC, will that be OK? Again, I would simply be a no-show and then SDC in the same way I could if traveling by myself.

Any info is greatly appreciated! TIA!