I don't have any reference links handy, but I have read comments from people who were developing 68060 accelerators that it was costing more than expected, and was more difficult to put into practice than hoped. It was deemed possible but not really worth bringing to market. Look at Czuba-tech's CT60, they made several 68060 Atari upgrades, but even in moderate quantity they were quite expensive and not entirely compatible (hence the bypass switch). It can be done! Maybe a retrocomputing philanthropist with lots of time, money, and brains will figure it out and I might be able to afford the end product.