Garageband on iPhone: In need of some conceptual hints

iOS & iPadOS

Hello everyone!
Since I'm new here, I thought I'd begin with a very brief paragraph of introduction: My real name is Felix, I'm from Germany, I work as software developer in assistive technology, and I'm blind. I'm a huge fan of a lot that Apple has done, and is doing, accessibility-wise. It's great to be here, and I hope I'll be able to both contribute and learn a lot while being here.
I'm currently teaching myself to use Garageband on an iPhone, using an iRig Keys Pro midi controller to play software instruments, with some success. I intend to share my findings here in the form of a guide at some point, when I get around to writing it. And if my music serves as conceptual demo I'll share that as well.
For the time being, however, it seems that I am the one in need of some guidance. Especially, I can't seem to figure out how to do basic things like trim a region, trim a sample (as in: using the sampler) or extend the length of a looping track. I find it's hit and miss, sometimes reading the time as I drag, sometimes not reading it, sometimes not even moving the slider that I'm trying to move. Also, actions on the rotor of a region, like trim or loop, are there but when I select them and double-tap more often than not there is no feedback, and I can detect no difference afterwards.
The most frustrating thing, however, is that Garageband has a terrible tendency to crash when I switch from tracks view to perform view, when I undo an editing operation, or even when I try to exit out of the song so that it saves. I've lost quite a bit of editing this way. Irretrievably, I might add.
So my questions, to which I hope someone on here might have an answer, are:
1. Does anyone have an idea how to prevent those very frequent crashes?
2. Is there any documentation, or similar content, regarding editing tracks and regions with Voiceover?
Thanks in advance!