gnome - Running a long command, split into multiple lines, in a .desktop file?

Say we have this file, start-term-tabs.sh:

gnome-terminal \
  --tab --title="Term 1" \
    --working-directory=/tmp \
    -e "bash -i" \
  --tab-with-profile=Default --title="Term 2" \
    --working-directory=/home \
    -e "bash -i" \
  --tab-with-profile=Default --title="Term 3" \
    --working-directory=/etc \
    -e "bash -i"

Because this is a long command, and for readibility reasons, I like to split it in multiple lines, by escaping the line feed on each line. By doing chmod +x start-term-tabs.sh, I can double-click the start-term-tabs.sh on the desktop and it will start, but it will show the super-annoying 'Do you want to run "start-term-tabs.desktop", or display its contents?':

... on which I have to click "Run" each time.

Now, I could make a test.desktop file like this:

[Desktop Entry]
Name=start-term-tabs test
Terminal=false
Type=Application
Icon=/usr/share/app-install/icons/terminal-tango.svg
Exec=/home/USER/Desktop/start-term-tabs.sh

... and after doing chmod +x test.desktop, everything runs; but then I have to manage two files, and I'd instead like to manage only one file.

So, I tried tucking in the entire above gnome-terminal command line in there, and when it is as a single line in the Exec field:

Exec=gnome-terminal   --tab --title="Term 1"     --working-directory=/tmp     -e "bash -i"   --tab-with-profile=Default --title="Term 2"     --working-directory=/home     -e "bash -i"   --tab-with-profile=Default --title="Term 3"     --working-directory=/etc     -e "bash -i"

... it also does work fine, but it is quite difficult for me to manage it when it is on only one line.

But when I try to split it inside the .desktop file, that is:

[Desktop Entry]
Name=start-term-tabs test
Terminal=false
Type=Application
Icon=/usr/share/app-install/icons/terminal-tango.svg
Exec=gnome-terminal \
  --tab --title="Term 1" \
    --working-directory=/tmp \
    -e "bash -i" \
  --tab-with-profile=Default --title="Term 2" \
    --working-directory=/home \
    -e "bash -i" \
  --tab-with-profile=Default --title="Term 3" \
    --working-directory=/etc \
    -e "bash -i"

... then as soon as I save this, the icon is not shown on the .desktop file any more, that is it starts looking like this:

... and so it is not treated as a valid .desktop file, so when it is double-clicked, again I get the "Do you want to run..." prompt, and even if I say Run, no gnome-terminal is started, so something ends up horribly here.

So, how could I split a long command for the Exec field in a .desktop file in multiple lines, - possibly using some sort of escaping - and still have it run properly?

I've seen https://specifications.freedesktop.org/desktop-entry-spec/desktop-entry-spec-latest.html#exec-variables, and I've tried using \\ everywhere instead of just \, but that doesn't help - and I otherwise cannot tell what I should do to get this working...