To do an interleaving FPGA is relately straight forward. You would have to find one fast enough and be able to program it.
85Hz monitors are special application monitors. I would go back manufacturer and see what was meant to drive these monitors. More then likely it was special high resolution camera connected over analog cables or custom designed generators.
Currently the technology is at 4k x 2k @ 30Hz with it going to 4k x 2k @60Hz These are the standard monitors/TVs
Check the pixel rates you are dealing with here 2048x1536@85 => 2048x1536x85*1.1 = 356MHz pixel rate if you go digital.