Is there any tool or process you would recommend that can take a standard stack of Gerber files (usually 2-layer, although the potential capability to support 4-layer would be nice) and bring them all together into one set of Gerber files on a combined single panel for fabrication, for fab houses where this is required or economically attractive.
I want to do this in a way that isn’t labor intensive, doesn’t corrupt or change the existing Gerber files, and takes Gerber files as its input, meaning it is independent of whatever EDA/CAD software is used by different people – Altium, Eagle, KiCad, whatever – as long as they’re just able to generate and provide standard Gerbers from their software.