Welcome to the forum, Fadil, and thanks for your feedback.
Dorico for iPad has broadly the same feature set as the desktop Dorico SE when you use it without a subscription or the Lifetime Unlock in-app purchase, and broadly the same feature set as Dorico Elements when you have a subscription or the Lifetime Unlock.
At the present time, Dorico Pro is the only version of the software that provides support for custom tonality systems. However, I am sympathetic to the view that using extended tonality is something that is not optional for certain kinds of music, and that we should consider broadening access to these features. We’ll definitely give this serious consideration for the future.