Bought physical SE from SE store, haven't received it, no tracking number given.

[worldofneil]

If I were to buy a standard physical copy elsewhere, would I be able to input my CE code if it ever arrives?

Unlike 1.0, ARR 2.0 doesn't have a separate code for the collectors edition items and there's a massive thread on people that were caught out on this change. So if you register standard to your account, you can't then upgrade it to collectors with a physical code, adding that code would add a second account.

You could however add a standard version then do the digital upgrade option (from the mogstation website I believe) to collectors edition and then cancel/get the CE physical version refunded.

I know that's not a lot of help if you wanted the actual physical box though, but it's really that or wait/chase SE for it