Also, I was able to change the RSS feed by utilizing a custom excerpt made by enabling excerpt from the Screen Display option. But I ran into the two issues described in my original post.
]]>When you add a custom excerpt, you are not just changing the RSS feed. You are changing what shows on your site (wherever the excerpt is used). And the Screen display options only need to be set once per user. After that, the user meta value that the user wants to see it is stored so it shows correctly next time.
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