Learn Farsi: آنها کابین‌ها را برای بیشترین آسایش طراحی کردند. - They designed the cabins for the utmost comfort.

This is the absolute use of the superlative -tarin. Instead of meaning the most comfort compared to something else, it just means extreme or utmost comfort. In Farsi, you can use superlatives this way to emphasize a maximum degree without making a direct comparison.

Why isn't there an ezafe linking bishtarin to asayesh?

Superlative adjectives ending in -tarin always come before the noun they modify, and they do not take an ezafe. This is a strict rule in Farsi grammar, so it is just bishtarin asayesh without any connecting vowel.

Is there a difference between asayesh and aramesh since both can mean comfort or peace?

Yes. Asayesh refers to physical comfort, convenience, and material well-being, which is exactly what you want when designing a physical space like a cabin. Aramesh is used more for mental or emotional peace and tranquility.

Why does ra come immediately after kabin-ha instead of later in the sentence?

The word ra marks the specific direct object, which is the cabins. In standard Farsi sentence structure, the direct object and its ra come before prepositional phrases like baraye bishtarin asayesh. So the order is: Subject + Object + ra + Prepositional Phrase + Verb.