There is a number of limitations implied by application objectives and design choices which are expected to be final and would not be re-considered in future application versions. Some of them may interfere with your usage expectations.
When requesting a new feature, ensure its absence reasons are not covered by this list.
Small, fast & functional. Good choice for the guest OS of machine emulator.
This does not mean it is not possible to use other operating systems like Debian. You are free to install whatever you want inside the VM, but do not ask me how to do this or report that new OS is very slow or does not work.
My personal choice for running software under other systems is Docker.
Only important & easy to implement things: console, special keys row, context menu for extra actions, application user guide. My occupation is not related to Android development, sorry.
If you need something that is more customizable, please use Termux instead.
It can run Alpine Linux in QEMU as well (recommending to try proot -
it's faster).
Do not request KVM, TUN/TAP and other features requiring rooted devices. I don't root my device and would not suggest rooting for others.
If you need to use advanced functionality of QEMU, I'm suggesting to use Termux instead. Its QEMU packages should have support of KVM and TUN/TAP.
System emulation adds significant computational overhead and execution of same task in QEMU uses much more energy than running it on host.
Emulator performance is enough for performing most of tasks, assuming your host CPU is fast enough. You can even perform fairly heavy tasks like compiling software. However it is not recommended to perform really heavy tasks like video processing, unless you have indefinite amount of time for waiting and want to turn your device into portable hand heater.
See sysbench performance comparison between vShell and Termux PRoot:
According to benchmark, vShell is 10 times slower than Linux distribution
inside proot (AArch64). However be prepared that actual performance in
certain cases could be lower and may depend on used software or host device.
Don't even try to root your device with vShell. This is not possible.
You can't use this application for accessing your USB-OTG drives, smartcards, SDR, Wi-Fi or Bluetooth dongles and other hardware.
I would not leave comments for those who think can elevate privileges by using QEMU.
vShell is a "virtual shell", isn't it?
You can install a VNC server inside, but I do not guarantee that graphics would be very useful for you due to low performance.
This limit arises from a fact that vShell doesn't use QEMU as external program. Instead it is merged with terminal emulator code. It is possible to implement multiple sessions but will require lot of work.
Use tmux or other multiplexer instead.
Serial lines transfer raw data. They have nothing to do with terminals and thus do not have fancy features like screen size handshaking.
Utilities reset and resize are your best friends when it comes to fixing
console glitches.
What else you will expect from application providing a VM with Linux distribution?
In order to successfully operate a Linux-based system, you need to know how to work with it. There are a lot of books, articles and blogs about this topic on the Internet. Begin with basics, set goals and accomplish them. Try online courses and challenges to keep your skills up.
You can use this application for practice, if you have learned some basics.
I do not provide mentorship. That's right up to you what software to install, how to use it, etc.