For a one-off cameo that wasn’t even written in the script? Absolutely not.
Rand is credited as "Woman in Cafeteria", but Nimoy decided that a cameo as Rand would be perfect for the scene of Enterprise's return. Despite the command rank on her uniform (ie. the scene was filmed at ILM and that was the only jacket that was sent across from Paramount). Having helped her out in Brisbane and Sydney, in 1982, I was luckily to meet up with Grace again in LA in the months just after filming (January 1984) -- and someone else I had caught up with said, "Will you be seeing Grace? It was so great to catch up with her at the [ST III] wrap party."
"Why was Grace at the wrap party?"
"Oh. I did
not tell you that she's in the movie."
When I saw Grace, I told her that I had accidentally found out. And she was so glad not to have to pretend. She didn't tell me any plot, of course, but she did intimate that her new rank was much higher than Yeoman/Chief.
When the movie came out, we saw that it was a Commander insignia.
Interestingly, and totally coincidentally, Rand is an extra character in Vonda McInyre's ST II novelization, even though she wasn't in the script nor the movie. Rand does not appear in Vonda McIntyre's ST III novelization, but... there was a reference at the end of Vonda's ST II that the cadets and injured crew were being transferred to the USS Firenze. So obviously Rand accompanied them and arrived home early.
Grace Lee Whitney by
Ian McLean, on Flickr