In order to get all three LinuxRT variants to have ALL of the features functional the following needs to be done:
Ensure that BusyBox is configured such that telnet is disabled entirely (neither set nor enabled)
Ensure that BusyBox is configured such that SUID is enabled (set and enabled)
The starting point of the BusyBox config file comes from site/config/bb-1.25.x.config, which you need copy from the .config you construct from running make busybox-menuconfig . For 2019-08 it's site/config/bb-1.29.x.config. This file is set in the BR2_PACKAGE_BUSYBOX_CONFIG which is in the br-2016.11.1-common.config file (for 2019-08, it's in site/br2-external/configs/br-common.config).
Ensure that BuildRoot is configured such that the password method is sha-256 instead of md5.
Although Eric didn't check them in yet, the rest of the changes in his site directory (which are essentially all of the changes that go into the RFS itself) work as expected (these are the changes for all of the user/groups and the /etc/SLACproperties file).
