Upgrade kit for the A3640 (2 wait states removed)

[psxphill]

I naiv assumed is that one of the reasons for the slowness of the 3640 might have just been "time-to-market".
E.g as soon as it worked it was sold - without giving the developers time for tuning.

As it's commodore, you can assume they sold it before it worked. An insight into what was going on at commodore at the time http://www.wonkity.com/~wblock/a4000hard/defibust.html

Whether those wait states are ever required is something that anyone doing this upgrade will have to consider, with the hack it might only work in a limited combination of a3640/buster/motherboard/phase of moon etc. If it works for you and you don't have an issue modifying classic hardware then I don't see the problem. If you have problems in the future then it will always be the first thing that you will doubt.
 
 Dave was human, he made mistakes. They might have been added under an assumption they were required, or they might not even have been intended. You could ask him, he might remember.

[psxphill]

Since, Commodore engineering was ordered to produce the cheapest possible 040 card, it's very easy to understand why they used the Motorola design with as few modifications as possible.

Section 7 from http://bitsavers.trailing-edge.com/pdf/motorola/68000/MC68040_Designers_Handbook_1990.pdf ?
 
 According to Dave the "cheapest possible 040 card" came out of engineering when it was going to be used in  the a3200/a3400.
 
 http://www.bigbookofamigahardware.com/bboah/product.aspx?id=1943
 
 "So, anyway, my buddy Greg Berlin was in charge of the A3200 and A3400, the only thing I did was fix his expansion bus when it didn't work. He was as annoyed about these models as everyone else, and so, kind of as a skunkworks project, he had Scott design "the cheapest '040 board known to mankind" as he put it, the idea being that, even if these systems went out and didn't impress anyone, we at least had this add-on to turn your A3200 into more or less an appropriate 1992-ish computer."
 
 Things didn't improve greatly when A3200/A3400 was killed to be replaced with the A4000. I think engineering were just grateful to be allowed to release a computer with AA.