In Garry's Mod, how to make a copyable composite prop spawner?

Sorry for a possibly weird question form, but my problem is as follows:

I want to create a prop spawner that would spawn not a single prop, but a set of welded together ones. I can do that just fine using Advanced Duplicator 2 by right-clicking the contraption and then hitting R to make a spawner. However, whenever I duplicate the resulting spawner (such as in order to save whatever I built with it), the duplicated spawner becomes faulty. It either spawns only one prop of the original set, without others welded to it, or spawns all of them, but the whole spawned contraption flies away at great speed upon appearing. In rare cases none of that happens and it duplicates properly, but the chances seem to be random. That's for a solo spawner, if I weld it to some other contraption (like making a cannon with projectile spawner inside) it will always be copied as faulty. As a result, I'm unable to save contraptions that use composite prop spawners. Any ideas how to fix or workaround that? I have AdvDupe 1, 2 and Wiremod installed.