AFAIK, the unpatchable vanilla SC4 was (still is?) only issued when you bought the game via Origin.
That's correct.
I've had a couple random people in the past year or so try to tell me Origin fixed the unpatchable ones again (they actually for a brief time did, after I sicced PC Gamer on them in 2014, but they reverted back when no one was looking). But I've yet to see any proof of that, and suspect they might actually be people with the free CD Key redemption copies.
Free copy from CD Key Redemption = Version 1.1.641 (fully patched)
Copy purchased from Origin Store = Version 1.1.610 (unpatched, and unpatchable, due to DRM replacement changing the checksum)
-Alex