All Avenue 510 plans include every export format: Horizontal (16:9), Vertical (9:16), Instagram (4:5), and Tall (3:4). Every format delivers at full 1080p: 16:9 for MLS, YouTube, and websites, 9:16 for Reels, TikTok, and Stories, and 4:5 or 3:4 for the feed. No format costs more than any other, and no plan withholds one.
What is worth understanding is how they are produced. All four come from a single render. Your clips are generated once, and each format is a crop of that same master at its own canvas size, which is why adding a format costs no extra credits. 9:16 is the tightest crop of the four, so it keeps the least of the width. Frame your scenes for it if vertical is the job.
In practice: if you want a horizontal tour and feed posts, pick 16:9 once and you are done. If you want a horizontal tour and a full-height Reel, those are two separate tours.

You choose what to render on the orientation screen, before the storyboard opens, and the picker counts what you have chosen before you commit. On the finished tour, Step 06 puts a switcher above the player so you can move between the formats that render produced and download whichever you need. Switching there costs nothing and regenerates nothing.