Can Latex inner tubes be patched? I've personally never ridden on Latex inner tubes.  

If I get a puncture on a latex tube I'd prefer to be able to fix it, given they're a lot more expensive than regular butyl tubes.

My research suggests 


No, nothing works, you need to replace the whole tube whenever it punctures
No, but you can knot them to isolate the hole and then reinflate for the ride home, where you replace the tube.


and


Yes, with regular tyre patches and vulcanising fluid, 
Yes, with regular tyre patches and rubber cement
Yes, with latex patches cut from another latex tube, and rubber cement
Yes, pre-glued patches (ie "stickers")


But for everyone claiming one of the solutions works, someone else says that it doesn't work.

Is it possible to Patch a puncture on a latex inner tube?  and is the patch permanent or only a get-home fix ?
It is possible to fix both latex intertubes for clincher tyres and latex inner tubes inside tubular tyres. 

Whether you'll be able to do it, depends on your ability to do it. 

As you suggest, using a patch made from another latex tube and glue will work. This webpage suggests using tubular rim glue instead of normal patch glue for better results. 

That webpage also gives detailed instructions on how to mend a punctured tubular tire.