So I just installed a new 11-34 range cassette on my tourer, and the additional teeth required that I add two links to my chain. I had run out of links on the chain I was running, but I did have another chain lying around. The original chain is a Shimano HG-93, and the two fill-in links are SRAM PG-950.
The SRAM links are both being held to the Shimano chain with Shimano HG-93 pins, which from what I can tell have a slight lip to them. Also, both connections to the Shimano chain have Shimano outer plates and SRAM inners. Other than aesthetically I haven't noticed any rough spots in my pedal stroke from the change.
I've done this type of lashing-together-chains thing before, but only with two SRAM chains (970 and 950). The way I'm figuring it, since the HG-93 pins are holding together the outer plates on both connections I should be okay, but I just wanted the pick the collective brains of BF to see if anyone had done this (or something like this) before. I'd much rather do this than pay another $20-30 for two more links.