For most blogs and articles of 1500 words or less optimizing for one search term per article or post is recommended. However there are some cases where dual-optimizing a single piece of content for two or more search terms may be required.
If your post exceeds 1000 words, it is recommended that content writers split the content into two smaller optimized drafts -- one draft optimized for each search term. Optimizing shorter posts of less than 1000 words for multiple search terms may result in unnatural sentences and is not advisable unless the two search phrases have similar semantic indices.
By splitting longer articles into two ore more sections and optimizing each section independently, multiple search term optimization can be applied more naturally -- without the risk of accidentally removing terms from the semantic index.