Using these locking tubes to keep the gas struts up, is a dangerous solution, in my opinion: the lower fixing points of the gas struts are not designed to take such a heavy load. Imagine, they crash when someone is standing under it.
The tailgate, if coming down, is not coming down smoothly, but like a guillotine...
A solution, if at all, is to use a very strong (telescopic) stick, to support the tailgate. Do not put the lower end of the stick on the ground (you may push it away accidentally), but fix it firmly with screws or otherwise on two positions: in the lower left corner of the clothing cabinet, just above the bumper. And firmly fix it in the tailgate too.
See this diagonal solution from our brilliant colleagues at Caliboard.de:
View attachment 81432
I partially "quote" a very tiny part of the much larger photo, if not allowed, please delete it.
Regards from Amsterdam,
Marc.