However there is a complete discrepancy between what you suggest and
what is explained in the

"Getting Started Guide"
https://nw-digital-radio.groups.io/g/udrc/wiki/DRAWS%3A-Getting-Started

In the above guide is written to execute script app_config.sh core in Initial Configuration.
On the contrary you wrote

https://github.com/nwdigitalradio/n7nix/blob/master/docs/IMAGE_README.md)
come pre-installed on the nwdr14.img. Running the install scripts on
this image is not necessary and most likely will break things.

The nwdr14.img comes with installed software. You must do the initial
configuration. app_config.sh is a configuration script not an
installation script. Do not run the install scripts over the
pre-installation on the image.

You can see a log of what is already installed here:
cat /var/log/udr_install.log

However, direwolf is not installed in nwdr14 image.

Direwolf is part of the core install and is on the nwdr14.img.
From log file:
2019 09 19 11:03:22 PDT: core_install.sh: core install script FINISHED
Run sudo ax25-start to enable it as specified in the 'Getting Started Guide'

direwolf -v 2>/dev/null | grep -m 1 -i version
Dire Wolf DEVELOPMENT version 1.6 C (Sep 19 2019)

Immediately after first initial distro configuration ax25-status shows
that AX.25 pplications are not RUNNING and NOT ENABLED.

Yes, by design. The image will run HF programs by default unless you
run ax25-start.

Executing ./ax25-start fails with error code due to direwolf port not
found. There are a few reasons for this. First /etc/direwolf.conf is
not configured for DRAWS device is commented together with PTT GPIO is
not set to 12 (default left DRAWS plug).

Because you haven't run ./app_config.sh core
See 'Getting Started Guide'

In order to check if AX.25 is now correctly set up I started YAAC
application and listening to APRS frequency.

No stations could be decoded.

I had to execute setalsa-udrc-din6.sh script.

See 'Getting Started Guide'
* You must set your ALSA configuration for your particular radio at this time

At this step, to be able to get a functioning APRS application I found
it is abolutely necessary to switch Raspberry Pi power OFF and ON to
reboot. Otherwise, direwolf is not getting DRAWS audio.

ax25-stop followed by ax25-start will also work.

After these mandatory successive procedures, measure-deviate script was
found to be working correctly and beacon application could also be
activated.

The udrc port assignments are defaulting to a udrc II. You can fix that
by running the chk_port.sh script. The latest config scripts should do a
better job of setting the udr ports. ie when starting from a fresh image
always do a 'cd n7nix ; git pull' first. For the DRAWS hat the default
is to set the left mDin6 connector as udr0 for packet (winlink)
connections. You can change the config files to use the right mDin6
connector by running chk_ports.sh -n 1 -e

~/n7nix/bin $ ./chk_ports.sh -h
Usage: chk_ports.sh [-d][-e][-h]
Displays or edits: axports, ax25d.conf, channels.xml, wl2k.conf
No command line args, will display port names in above files.
-d set debug flag
-e set edit files flag
-n 0 or 1 set winlink device number, only used with -e option.
-p print files with port names.
-h no arg, display this message

pi@checkcfg:~/n7nix/bin $ ./chk_ports.sh
== AX.25 network ports check
Device ax0 OK, and up
Device ax1 OK, and up

== file: /usr/local/etc/ax25/axports check
axport: found device: udr0, with call sign N7NIX-10
axport: found device: udr1, with call sign N7NIX-1

== file: /usr/local/etc/ax25/ax25d.conf check
ax25d: found device: udr0, with call sign N7NIX-10
ax25d: found device: udr0, with call sign N7NIX

== file: /etc/rmsgw/channels.xml check
RMS gateway: chan_name: udr0, call sign: N7NIX-10

== file: /usr/local/etc/wl2k.conf check
plu: ax25port: udr0, call sign: N7NIX

/Basil