I just had an idea. Maybe there could be an easy alternative to double-threaded radiators that would allow us to connect any two radiators together.
I tried to illustrate with a quick sketch:



There is something similar available for connecting two GPU waterblocks. Example: Link
All that needs is another G1/4" thread in the middle and you've got a T-line for connecting two radiators in paralell. The radiator-threads could then simply be facing each other.
What do you think? Would this work?