I didn't have the cash for new lift struts and did the same thing, that wood prop I was using seemed to always get knocked out and slam down on me, with the strut tube holds I never have to worry about it falling, they do not rattle and they are always there when you need them, plus I didn't care for the fact that with new struts when you open the hatch they power it all the way open and then you have to pull it down and push it close with no type of handle at all.
Do you drive down the road with the lift gate open?
Sometimes. If I have a really bad day at work. I get all "this is the last time I'm taking this drive ..." I open the lift gate and start my drive home then I hit a bump and the lift gate closes and I end up safe and sound at home. Don't even get started on rattles. I hate rattles. No more of that bullcrap for me. Next time I want to asphixate myself, copper pipe for the MF win! lol.
Honestly, I wouldn't think the copper pipe would fit to tight on the strut housings and might rattle a bit even when closed.
I use the same idea but instead I use a piece of PVC split down the side just enough to clip on the lift rod and the appropriate cut length. Clip off and lay next to door when not in use, until I decide to replace the lifts.
Back in 09 my friends jeep rear hatch decided to assault me after the prop she used to hold it up gave way. After that i started pricing new lift supports, $29 later off of eBay for a set i haven had any issues since with it or any more knots on my head!!!!.....
The spacers are a nice Temporary idea at best!!!!!!, but better just to get the new lift supports and be finished with it!!!