Jonas Grumby wrote:
^ Given the stellar acting opportunities provided by the "zombie Spock" scenes, I'd have to figure Nimoy's request was based on quantity of screen time rather than quality of screen time.
That would be my take as well.
Given the requirements and pressures of TV acting at that time, LN might even have been worried that he wouldn't be properly credited (and paid!) in that episode.
He was a co-star, a regular in the series, he had no worry about his credit if he was only in a few minutes of an episode. His credit would remain even if missed the episode entirely. Their salaries were negotiated as "per episode," not "per page" or "per line." It didn't matter how long any of them were in the episode. Shatner didn't lose any credit, or money for being absent for most of The Tholian Web. The concern had to be purely screen time.