I was getting sick of looping a lanyard around my tail plane to hold back my model when starting. The lanyard would get caught on the elevator or on the tail wheel, and was just a nuisance, so I thought I would print something more practical.
This is what I came up with.
I haven't used at the field yet but it works well on static testing.
I am sure that it will be strong enough for up to a 30cc gasser, but advise you to make sure that you check with your setup to ensure that it has adequate strength for your application.
I am happy with the ease of putting on and off.

Update;
Just pull tested one of the clips to check strength. The clip lifted 10kg easily without showing any signs of failure. This gives over 100% safety margin with my DLE30 (maximum static trust of 8.5kg)...very happy with that...

Creality

Ender 3

No

No

0.2

20%

No post processing required other than to assemble the handle to the supports.
The handle was a tight fit, so some sanding might help.