With the area that they have to work with, I'd say they have the potential to work with something that's longer than Hyperia and could be comparable to other multi launches or RMCs.
If Rumba Rapids and/or Stealth get removed, it'd potentially double the space it could use for a coaster of this nature.
Knowing Merlin and how they tend to restrict length of their coasters, I wouldn't be surprised if it's on the shorter side.
Shorter coasters could mean shorter rides, lower capacity, longer queues, repeat rides and more fast tracks 🤣 I'm sure fast track is a consideration for some of these coasters 😂