The title's ironically quite correct.
Per
https://www.aaroads.com/forum/index.php?topic=32145.msg2770302#msg2770302, I drove up to St Helens today to field check this, and Bus 30 is well signed along eastbound Gable Rd and Old Portland Rd, and in both directions along Columbia Blvd. The photo in the AARoads thread is at Old Portland and 1st. No BUS US 30 assemblies, all green interstate shields.
No signage from US 30, however.
This isn't an ODOT recognized loop, as that was decomissioned a while back, if ever a formal ODOT route (I don't see a decom entry for US 30 Bus in the Oregon Named Highways list); I doubt AASHTO heard of this without diving into the AASHTO thread at AARoads.
As the route is well signed in the field: Do we add this to our database, and if so, as US 30 Bus, or as signed as I-30 BL (despite being nowhere close to I-30 itself)?
If not, at minimum, the StHelSt point for US 30 needs to be looked at to see if it should changed to ColBlvd, as that's the dominant portion of the St Helens St/Columbia Blvd couplet.