VMs end up locked out on Digital Ocean

I have tried the following disk images on Digital Ocean and found they do not work:

Specifically, in each case the VM starts and ping works, but the VM does not allow to log in over SSH using the pre-configured public SSH key: neither root not alpine work. With VMs installed from Digital Ocean selection of Linux distributions this works. On the VM web/VGA console there are only the following lines:

Loading vmlinuz-virt... ok
Loading initramfs-virt...ok

Pressing Enter does not return a login prompt. The only potential way to recover the VM is to boot from a virtual rescue CD (not tried).

Following this experience, I tried the same disk images in a local VirtualBox and observed exactly the same [lack of] output on the VGA console. However, I was able to recover the VM and gather some diagnostics as to why the problem occurs and how it could be fixed. Let me state some facts first:

DO VMs use SeaBIOS and start booting from virtual disk after a very short delay.
DO web/VGA console takes several seconds to attach to a VM, disconnects during the VM power-cycle and does not allow to send Ctrl-Alt-Del.
After the VM has booted as described above, the only way DO provides to restart it is power-cycling.
In the above images syslinux boot timeout is 1 second.
In the above images the only console parameter in the default kernel command line is console=ttyS0,115200n8.
DO does not implement serial port console for VMs.

In the above images /etc/inittab includes the following lines, which do not change automatically, although another Linux user points out this code looks like it is supposed to uncomment them conditionally:

#tty1::respawn:/sbin/getty 38400 tty1
#tty2::respawn:/sbin/getty 38400 tty2
#tty3::respawn:/sbin/getty 38400 tty3
#tty4::respawn:/sbin/getty 38400 tty4
#tty5::respawn:/sbin/getty 38400 tty5
#tty6::respawn:/sbin/getty 38400 tty6

In a VM installed from the "standard" ISO image the above lines are not commented and VGA console is perfectly usable from the very beginning.
In VirtualBox it is possible to see the VGA console before syslinux starts, to interrupt the boot timeout, to change kernel command line and to access the virtual serial port; this is more than sufficient to recover the VM without using a 3rd-party rescue boot.

This allows to state the following problems with the above disk images:

Using DO, it is impossible to change boot parameters. By the time a DO user can access the VGA console, syslinux boot timeout has long expired and the boot has commenced with the default kernel arguments. Suggested fix: raise the timeout to 10 seconds.
It is impossible to log in from the VGA console after boot, no matter how hosted. Suggested fix: do not disable standard getty by default.
It is impossible to monitor/debug boot progress on the VGA console, no matter how hosted. Suggested fix: use console=tty0 console=ttyS0,115200n8 to send kernel boot messages to both VGA and serial port.
Neither cloud-init nor Tiny Cloud work with DO infrastructure, another Linux user points out this is likely because DO expects specific arrangements in the VM configuration.

Please review.