The phrase "yet maintain" is correct and usable in written English.
It can be used to indicate that something is being preserved or kept despite other circumstances or changes.
Example: "She was able to adapt to the new environment yet maintain her original values."
Alternatives: "but still uphold" or "and continue to preserve".
Shows that have an intellectual dazzle yet maintain an emotional strength in their secret hearts.
"We are slowing down to conserve parts yet maintain production as much as possible".
They have very few material possessions yet maintain a tradition of wearing silver jewelry that they make by hand.
They move with the explosive force of martial arts and yet maintain the poise and flow of t'ai chi and the quiet intensity of meditation.
This sense of impeding reality is what drew Hamm to Black Mirror, where "things are close enough to touch, and yet maintain a sense of science fiction.
Trying to attract artists to downtown and yet maintain the character of a fast-growing area, developers are preserving old buildings rather than razing them.
They support free elections in Egypt and Tunisia, and yet maintain the closest of military and security relationships with a government in the UAE that does the opposite.
In Hardy's world, life could be bleak yet still picturesque; in Lawrence's, madness could be chilling yet maintain a mysterious attraction.
There is a fiction that holds that journalists and their subjects can eat and socialize together and yet maintain the distance necessary to continue performing their professional roles.
Without the advantage of a bright screen, we needed them to pop off the page yet maintain as much shape as possible when printed.
One of his assets in Barcelona was his ability to grow close to his players yet maintain the distance an authority figure requires.
