My thought was along the line that the FPGA projects are not fully compatible yet with the originals. And there exist lot of broken Amigas where only the motherboard is the broken part but the chips are ok. So then the idea is how feasable it would be to create a replication of the original motherboard.
Only sockets and ports need to retain their mechanical position. The rest could be optimized. Perhaps new PCB technique allow 2-layer board for the same job?