Hi Mike,
There wasn’t anything reported that I could see in our system for Alembic having any issue with this flag. I checked in 4.13, 4.14, and 4.15 and all seemed to be working for me that I could see.
I have a simple .abc test asset. I drag in a default Decal Actor. I then select the test asset and in the Details panel I disable “Receives Decals” and I can see it toggle on/off for the test asset.
This is what I did to check. If you have any additional info or test asset that doesn’t respect this setting can you please share that? I’ve included my test asset that works when I checked this.
Thanks!
Tim