Yes, the ACM08Y and the ACM26C (they’re the same thing really) report all 3, but they’re not in exact sequence (as lin 01 → 02 → 03 → 01 → 02 → 03… as it should be, but rather something like 01 → 02 → 01 → 02 → 03 → 01 → 03 → 02…) so I know they’re choking a bit on that.
The Sycreader R60D kind of does the same thing but worse - mostly due to the slowness of the “typing”, since it’s a keyboard wedge.
As for the Elatech Multitech TWN4, it works perfectly for a few seconds, then it falls into a coma for 10/15 seconds before it regains consciousness and sends the 3 UIDs again, only to fall into a coma again after a few more seconds.
I think the issue is that all the developers who made the readers’ various firmwares all assumed a continuous stream of EM sequences could only come from a single tag, and therefore could only yield a single ID. As a result, they paid no special attention to following fast UID transitions without “falling behind”, so-to-speak. It works more or less well on this or that reader depending on how gracefully the firmware happens to handle this totally unexpected situation