The new release v1.6.1 that addresses the problem with H9 Control being slow on 3rd and 4th generation iPads is available now through the Apple's AppStore.  I just downloaded and installed it on an iPad.

I noticed that the release notes are out of date. It's showing the release notes for the previous release instead of the new release. Apple completely changed around their submission process for apps a few weeks ago; it could be that we entered the release notes in the wrong place or it could be that their new process still has some kinks in it…

In any case the release notes should be the following:

This version fixes some performance problems affecting the app on 3rd and 4th generation iPads. It adds a new feature for universally editing and saving all instances of a preset with the same name, and it adds the ability to connect to CoreMIDI devices through the app and send their MIDI information to a connected stomp box.