You have a 12.9? Wow. Apple removed iDOS2 from the App Store and I've used Termius before.
Yes. iDOS2 was stellar, and I encourage anyone who can to side-load it onto their iPads. It is a game-changer for my use of the iPad for gaming, and
being able to load thousands of DOS games onto it is an absolute delight.
Other than Termius, is there something you've used on your iPad to telnet or SSH onto BBS'es?
--- Mystic BBS v1.12 A45 2020/02/18 (Linux/64)
* Origin: The Bottomless Abyss BBS * bbs.bottomlessabyss.net