I can confirm that busch gardens has the "red tabs" for kumba and montu, haven't looked for them on sheikra. However I haven't actually seen the harness in use. Also, they have a booklet full of EVERY single combination of amputations a person could have. Hands, feet, elbow, knee and every combination. For instance, the booklet will say
amputated
hand: 1
below knee: 2
can ride if all other conditions are met: yes
requires harness if all other conditions are met: yes
thats just a hypothetical, I don't actually have a booklet, but they've shown one to me when I asked. They told me they almost never have to use it, but it is useful when they do, and that they can point to the ruling in writing.